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DIAGNOSTIC IMAGING PATHWAYS This Thesis Is Presented for The

DIAGNOSTIC IMAGING PATHWAYS This Thesis Is Presented for The

THESIS TITLE: DIAGNOSTIC IMAGING PATHWAYS

This thesis is presented for the degree of Master of Medical Science by Research of the University of Western Australia by

Ravinder Dhillon (MBBS)

School of Medicine and Pharmacology University of Western Australia 2006

DECLARATION FOR THESES CONTAINING PUBLISHED WORK AND/OR WORK PREPARED FOR PUBLICATION

1 This thesis does not contain work that I have published, nor work under consideration for publication. The thesis is completely the result of my own work, and was substantially conducted during the period of candidature, unless otherwise stated in the thesis.

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Signature……………………………….

2 This thesis contains sole-authored published work and/or work prepared for publication. The bibliographic details of the work and where it appears in the thesis is outlined below.

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Signature………………………………

3 This thesis contains published work and/or work prepared for publication, some of which has been co- authored. The bibliographic details of the works and where they appear in the thesis are set out below. (The candidate must attach to this declaration a statement detailing the percentage contribution of each author to the work. This must been signed by all authors. Where this is not possible, the statement detailing the percentage contribution of authors should be signed by the candidate’s Coordinating Supervisor).

PJ Bairstow, R Mendelson, R Dhillon and F Valton. Diagnostic imaging pathways: development, dissemination, implementation, and evaluation. International Journal for Quality in Health Care 2006; Volume 18, Number 1: pp 51-57. The contents of this published paper appear in Chapter 3 (Medium of Distribution), Chapter 4 (Dissemination and Implementation), Chapter 5 (Evaluation and feedback) and Chapter 6 (Discussion) of this thesis.

Signature……………………………… Dr Ravinder Dhillon Clinical Professor Richard Mendelson (Coordinating Supervisor) Declaration

The contents of the paper titled “Diagnostic imaging pathways: development, dissemination, implementation and evaluation” published in the International Journal for Quality in Health Care 2006; Vol 18, Number 1: pp 51-57 form a part of this thesis and I have the permission of the co- authors - Dr Richard Mendelson, Dr Phillip Bairstow and Mr Frederic Valton, to include this work in my thesis.

Dr Ravinder Dhillon Dr Phillip Bairstow

Clinical Professor Richard Mendelson Professor Ian Puddey (Coordinating Supervisor) (Co-Supervisor)

ii Contents

CONTENTS...... ii THESIS ABSTRACT...... vi CONTRIBUTIONS TO THESIS...... viii PUBLICATIONS AND PRESENTATIONS...... xi ACKNOWLEDGMENTS...... xii

CHAPTER 1: Introduction 1.1 Introduction...... 2 1.2 Hypothesis and Aims...... 7 CHAPTER 2: Clinical and academic content 2.1 Objective...... 9 2.2 Methodology...... 9 2.3 Results...... 10 2.4 Diagnostic Imaging Pathways...... 12 Cardiovascular system • Abdominal Aortic Aneurysms...... 13 • Blunt Traumatic of Thoracic ...... 15 • Deep Thrombosis...... 19 • Hypertension...... 22 • Lower Limb Claudication...... 26 • Spontaneous ...... 29 • Suspected Myocardial Infarction...... 32 • Acute Headache...... 36 • Chronic Headache...... 40 • Cord Compression...... 44 • Dementia...... 47 • Head Trauma...... 52 • Investigation of Seizure...... 54 • Orbital Pathology...... 59 • Pituitary Fossa Lesion...... 62

iii • ...... 64 • Transient Ischaemic Attacks...... 68 Ear, Nose & Throat • Chronic Sinusitis...... 72 • Salivary Gland Swelling...... 76 • Tinnitus...... 79 Endocrine System • Densitometry...... 82 • Incidental Adrenal Mass on CT...... 84 • Investigation of Cushing’s Syndrome...... 87 • Phaeochromocytoma...... 90 • Primary Hyperaldosteronism...... 93 • Primary Hyperparathyroidism...... 96 • Solitary Nodule...... 100 • Thyroid Incidentaloma...... 103 Gastrointestinal System • Acute Bloody Diarrhoea...... 105 • Acute Gastrointestinal Bleeding...... 109 • Acute Left Iliac Fossa Pain...... 114 • Acute Pancreatitis...... 118 • Acute Right Iliac Fossa Pain...... 122 • Acute Right Upper Quadrant Pain...... 126 • Blunt ...... 129 • Chronic Pancreatitis...... 134 • Dyspepsia...... 137 • Dysphagia...... 141 • Imaging Prior To Laparoscopic ...... 145 • Investigation of Cholestatic Jaundice...... 151 • Staging of Colorectal Cancer...... 156 • Staging of Oesophageal Cancer...... 160 • Suspected Bowel Obstruction...... 163 • Suspected Intra-abdominal Abscess...... 168 Genitourinary System • Acute Renal Failure...... 172

iv • Acute Renal Transplant Dysfunction...... 175 • Lower Urinaray Tract Symptoms (LUTS) ...... 178 • Painless Haematuria...... 181 • Renal Colic...... 185 • Renal Mass...... 190 • Scrotal Mass...... 194 • Scrotal Pain...... 197 • Staging of Prostate Carcinoma...... 200 • Staging of Renal Cell Carcinoma...... 204 Musculoskeletal System • Back Pain...... 207 • Bone Metastases...... 212 • Cellulitis with Suspected Bone Infection...... 213 • Pain...... 218 • Multiple Myeloma...... 223 • Shoulder Pain...... 225 • Spinal Infection...... 229 • Spinal Trauma...... 234 • Suspected Avascular Necrosis...... 239 • Suspected Scaphoid Fracture...... 242 • Suspected Stress Fracture...... 246 Obstetrics & Gynaecological System • First Trimester Bleeding ...... 249 • Pelvimetry...... 253 • Suspected Ectopic ...... 255 • Third Trimester Pregnancy...... 259 • Bronchiectasis...... 260 • Haemoptysis...... 262 • Raised Hemidiaphragm on ...... 265 • Solitary Pulmonary Nodule...... 267 • Staging of Cancer...... 272 • Suspected Mediastinal Mass...... 276 • Suspected Pulmonary Embolus...... 279

v CHAPTER 3: Medium of Distribution 3.1 Methodology...... 287 3.2 Results...... 287 CHAPTER 4: Dissemination and implementation 4.1 Introduction...... 290 4.2 Methodology...... 290 4.3 Results...... 293 CHAPTER 5: Evaluation and feedback 5.1 Introduction...... 296 5.2 Methodology...... 296 5.3 Results...... 300 CHAPTER 6: Discussion 6.1 Clinical and Academic content...... 306 6.2 Electronic environment...... 306 6.3 Dissemination and implementation...... 307 6.4 Evaluation...... 307 CONCLUSIONS...... 309 REFERENCES ...... 310 APPENDICES...... Appendix 1...... 314 Appendix 2...... 317 Appendix 3...... 325

vi ABSTRACT

Hypothesis: There is deficiency in the evidence base and scientific underpinning of existing diagnostic imaging pathways (DIP) for diagnostic endpoints. Objective: a) To carry out systematic review of literature in relation to use of diagnostic imaging tests for diagnosis and investigation of 78 common clinical problems, b) To identify deficiencies and controversies in existing diagnostic imaging pathways, and to develop a new set of consensus based pathways for diagnostic imaging (DIP) supported by evidence as an education and decision support tool for hospital based doctors and general practitioners, c) To carry out a trial dissemination, implementation and evaluation of DIP. Methods: 78 common clinical presentations were chosen for development of DIP. For general practitioners, clinical topics were selected based on the following criteria: common clinical problem, complex in regards to options available for imaging, subject to inappropriate imaging resulting in unnecessary expenditure and /or radiation exposure, and new options for imaging of which general practitioners may not be aware. For hospital based junior doctors and medical students, additional criteria included: acute presentation when immediate access to expert radiological opinion may be lacking and clinical problem for which there is a need for education. Systematic review of the literature in relation to each of the 78 topics was carried out using Ovid, Pubmed and Cochrane Database of Systematic Reviews. The evidence thus gathered was graded using the Oxford Centre of Evidence-Based Medicine Levels of evidence. The earlier editions of diagnostic imaging algorithms were recalled and the deficiencies and controversies identified. An updated, modified or a new draft pathway was created based on currently available evidence. The evidence supporting the pathway was presented in the form of text dot points together with the references for each topic. Where nationally or internationally published and accepted guidelines were available, this information was coalesced into a draft pathway. The draft pathways were initially provided to the editors of the DIP project, followed by appropriate subspecialty imaging consultants and specialist clinicians. The draft pathways relating to general practice were provided to general practitioners nominated by the Royal Australian College of General Practitioners. The opinions and suggestions received led to revisions based on consensus and draft of additional pathways as appropriate. For selected topics, draft guidelines were presented at clinico-radiological meetings, and feedback

vii received was incorporated into the pathways and a “final draft” was produced based on consensus opinion. A new version of DIP was developed, and the clinical and academic content was loaded into a newly developed electronic environment for dissemination via a hospital Intranet or CD. A vigorous implementation methodology was employed involving two phases; viz raising general awareness of DIP and intensive marketing activities. The evaluation was mainly qualitative and had two phases; viz Assessment 1 at the onset of intensive marketing, Assessment 2 two months later. DIP was disseminated, implemented and evaluated in a hospital setting and in general practice. Intensive marketing of DIP was carried out in three hospital departments (Emergency Medicine, General Medicine, and General ) and with self-selected general practitioners. There were 54 hospital participants (mainly junior doctors) and nine general practitioners. Evaluation involved measurement of alignment between knowledge of diagnostic imaging and DIP (multiple choice questionnaire), alignment between requesting practice and DIP (examination of patient records), requesting clinician judgment of usefulness of DIP, barriers to use and suggestions for improvement (questionnaires).

Results: The clinical and academic content of DIP was of practical use. The electronic environment and the method of delivery provided a satisfactory medium for dissemination. Getting DIP implemented required vigorous effort. Knowledge of diagnostic imaging and requesting behaviour tended to become more aligned with DIP following a period of intensive marketing.

Conclusions: Systematic review of literature and input and feedback from various clinicians and radiologists led to the development of 78 consensus based Diagnostic Imaging Pathways supported by evidence. These pathways are a valuable decision support tool and are a definite step towards incorporating evidence based medicine in patient management. The clinical and academic content of DIP is of practical use to a wide range of clinicians in hospital and general practice settings. It is source of high level knowledge; a reference tool for the latest available and most effective imaging test for a particular clinical problem. In addition, it is an educational tool for medical students, junior doctors, technologists, and allied health care personnel.

viii CONTRIBUTIONS TO THESIS

1. My main contribution to the Diagnostic Imaging Pathways (DIP) project, in my capacity as a Research Fellow, is the “clinical and academic content” of the Diagnostic Imaging Pathways with further intellectual contributions to the dissemination, implementation and trial evaluation phases of the project.

2. I was responsible for conducting the systematic review of literature for the 78 clinical topics for which DIP have been developed and thus made a major intellectual contribution towards gathering and incorporating evidence behind these.

3. The text in the form of evidence supporting the algorithms in DIP which are presented in the clinical and academic section of the thesis is my original work with input from the editors and various radiologists and clinicians who have been acknowledged by name in the product.

4. I was also responsible for grading of the evidence according to the Oxford Centre of Evidence-Based Medicine Levels of evidence.

5. I was a member of the Steering Committee of the Diagnostic Imaging Pathways project. Members of the Steering Committee provided their expertise during all phases of the project. Membership (in alphabetical order) comprised Phillip Bairstow, Ravinder Dhillon, Judith Finn, Shauna Gaebler, Jacquie Garton- Smith, Natalie Gray, Carolyn Lawrence, Richard Mendelson, John Newman and Fred Valton.

6. The final clinical and academic content of DIP was edited by consultant radiologists - Clinical Professor Richard Mendelson and Dr Martin Blake. The Editors were responsible for coordinating all clinical input to the content of DIP.

7. The project Manager, Dr Phillip Bairstow, is responsible for the overall management of DIP.

ix 8. A large number of medical and surgical specialists and general practitioners provided input to determining the content of DIP. Individuals are acknowledged by name under "Contributors" on the developed website.

9. The Canning Division of General Practice (in particular Carolyn Laurence and John Newman) and the Perth & Hills Division of General Practice (in particular Shauna Gaebler) provided expertise and resources to all phases of the project, especially to the trial dissemination and evaluation.

10. The Royal Australian College of General Practitioners provided input to determining the content of DIP.

11. Heads of Departments of Emergency Medicine (Greg Sweetman), General Surgery (Sudhakar Rao) and General Medicine (Simon Dimmitt) at Royal Perth Hospital (RPH) supported the trial dissemination and evaluation in their departments, including intensive marketing activities.

12. Senior Registrars (Lai-Kun Kho and Michael Warner) provided advice regarding the dissemination and evaluation methodology deployed at RPH.

13. The Information Technologist (Fred Valton) was responsible for the design and functionality of the electronic environment. The Technical Assistant (Barbara Taylor) imported the content to the electronic environment.

14. The Research Officers, Lisa Towler for the hospital trial, and Taryn Hunt and Sarah Jones for the general practice trial, were primarily responsible for conducting the trial dissemination and evaluation.

15. The School of Population Health, University of Western Australia, in particular D'Arcy Holman and Judith Finn, provided advice and assistance particularly in the design of dissemination and evaluation methodologies, and in the analysis of data.

x 16. The Health Department of Western Australia, in particular Alphonse Roex and Sally Skevington, provided broad direction and approved core funding for the project.

17. The Division of Imaging Services at RPH, in particular the Director (Mark Khangure), provided accommodation and infrastructure for the project and released staff in carry out particular tasks.

xi PUBLICATIONS

1. Bairstow PJ, Mendelson RM, Dhillon R and Valton F. Diagnostic imaging pathways: development, dissemination, implementation, and evaluation. International Journal for Quality in Health Care 2006; Volume 18, Number 1: pp 51-57. 2. Ravinder Dhillon, Richard Mendelson and Martin Blake. Diagnostic Imaging Pathways in adults. Accessible via the Royal Perth Hospital Intranet and available to any computer that is logged into the network as well as available as a compact disc.

ORAL PRESENTATIONS

1. Ravinder Dhillon. Diagnostic Imaging Pathways. Medical Grand Round, Royal Perth Hospital, April 2003. 2. Ravinder Dhillon. Diagnostic Imaging Pathways. Intern Orientation Program, Royal Perth Hospital, January 2003. 3. Ravinder Dhillon. Dyspepsia – Evidence based diagnostic imaging pathway. Combined Gastroenterology/Surgery/ clinical meeting, Royal Perth Hospital, September 2002. 4. Ravinder Dhillon. Investigation of Renal Mass – Evidence based diagnostic imaging pathway. Combined Urology/Surgery/Radiology clinical meeting, Royal Perth Hospital, August 2002. 5. Ravinder Dhillon. Acute scrotal pain – Evidence based diagnostic imaging pathway. Combined Urology/Surgery/Radiology clinical meeting, Royal Perth Hospital, July 2002. 6. Ravinder Dhillon. Acute Right Iliac Fossa pain – Evidence based diagnostic imaging pathway. Combined General Surgery/Radiology clinical meeting, Royal Perth Hospital, June 2002.

xii ACKNOWLEDGMENTS

I would like to acknowledge and thank my supervisors Clinical Professor Richard Mendelson and Professor Ian Puddey for providing the guidance and support in every step of the research project and preparing this thesis. They have been invaluable source of advice and made themselves available and approachable.

I am thankful to Dr Phillip Bairstow (DIP Project Manager) and the staff of the Department of Radiology and , Royal Perth Hospital for their assistance in various forms throughout the duration of the DIP research project.

I am grateful to my family for their unconditional love and support. I thank my sister and brother for their academic input and assistance with proof reading and computer matters. I am grateful to my wonderful parents for their continual encouragement and for always being so proud of me no matter what the achievement. They helped me be who I am and instilled in me the courage to make my dreams a reality. Mom and dad, you have given me so many reasons to strive for better things.

xiii

Chapter 1

Introduction

1 INTRODUCTION

Diagnostic imaging has become a major driver of rising health care costs. In Australia it accounted for 15.5 per cent of Medicare benefits paid in 2003/2004 1, 2. The principle of 'public accountability' requires Government to ensure that public funds are expended appropriately but there are signs of inappropriate application of medical imaging technology to diagnosis. It is common for Imaging Specialists to give examples of unnecessary examinations being provided for particular clinical conditions, and for desirable examinations not being provided. A recent article cites previous research indicating that up to a third of radiological examinations are totally or partially inappropriate 3.

The problem of unnecessary and inappropriate requesting of imaging examinations is well recognised. In 1993, the American College of Radiology (ACR) determined that there was a need for nationally accepted, scientifically based appropriateness criteria to assist radiologists and referring clinicians in their choice of imaging examinations to arrive at diagnosis and make treatment decisions 4. Hence ACR appropriateness criteria for imaging were developed 4. Although evidence based, these appropriateness criteria do not include algorithmic guidelines. Rather than pronouncing on what is perceived to be the optimal investigation, the ACR lists all possible investigations and awards a score (out of 10) that indicates its appropriateness to the clinical setting. These have been developed using modified Delphi technique 4 with a consensus reached among experts. As these guidelines are designed for the American Health Care System, they are not necessarily applicable to Australian population.

The Royal College of Radiologists (RCR), London have their own set of imaging guidelines “Making the best use of a Department of Clinical Radiology: Guidelines for doctors” which have been developed by RCR Working Party 5. These guidelines list some relevant imaging techniques used in a particular clinical situation and make recommendations (and the grade of available evidence) on whether or not the investigation is appropriate. Also included are brief explanatory statements. However, the list of references relating to individual recommendations is not included in the guidelines booklet. Again these guidelines are not algorithmic guidelines.

2 There is increasing competition for scarce resources in the provision of health services, and consequently there is need to constantly aim for improvements in efficiency and cost-effectiveness of diagnostic imaging investigations. Operational expenditure on medical imaging services at Royal Perth Hospital in 1999/2000 was $16.1 million, and more generally, is a major component of total expenditure in the health sector. Estimates have been made of the incidence of examinations which are either unnecessary (not required for diagnosis or management) or inappropriate (incorrect for the particular circumstance), and the proportion is in the region of 10% 6. According to Dehn et al. approximately 40% of referrals to imaging investigations in the U.S were classified as inappropriate or at least not contributing to establishing a diagnosis 7. There is obligation to reduce expenditure on unnecessary or inappropriate examinations as far as possible.

Inappropriate diagnostic imaging has a number of potential adverse outcomes. Excessive examinations may expose patients to unnecessary risks 3, including the risk of false-positive results. Excessive imaging examinations result in increased radiation exposure which can result in detrimental health effects such as increased risk of long term development of cancer and genetic damage 3. On the other hand, failure to provide the most appropriate examination may result in inefficient diagnosis and delay in effective treatment. From the perspective of 'public accountability', inappropriate diagnostic imaging is a threat to the effective allocation of resources to health care.

“Inappropriateness” of imaging examinations can be classified as follows: 1. No imaging indicated • No relevant clinical question to be answered • No change in diagnosis • No management change would result 2. Incorrect choice of imaging • Wrong modality eg MRI better than CT • Correct modality, wrong technique (eg High resolution vs helical CT) 3. Correct choice of imaging but wrong timing

In some hospitals diagnostic imaging tests are being used as a substitution for careful clinical assessment 3. In complicated diagnostic cases the pre-test clinical probability often guides the diagnostic pathway. The results of the diagnostic imaging need to be

3 interpreted in conjunction with pre-test probability (Bayes theorem) 3 and thus guide patient management and further need for investigations. In cases where diagnostic imaging tests are being used as a substitution for careful clinical assessment, there is danger and risk of radiation exposure to patient and there are limitations to the interpretation of the diagnostic test.

We believe that a significant threat to appropriate diagnostic imaging is lack of knowledge. A 'medical knowledge crisis' is now well recognised, as is the need for improved knowledge management 8 and electronic decision support systems 9 in the health sector. Clinicians are often faced with situations requiring decisions as to what imaging examinations to request to assist in arriving at a diagnosis as effectively as possible. In the absence of a decision-making tool, they may request unnecessary examinations which may result in delay of diagnosis or may not request the most appropriate examination, thus not fully utilising aids to diagnosis. In an environment of increasing technological complexity and plenitude of diagnostic procedures, it is difficult for clinicians to choose the most effective and least invasive sequence of examinations to arrive at diagnosis. The task of keeping up-to-date with knowledge relevant to clinical practice is increasingly difficult due to the increasing volume of research activity and publications, clinical specialisation and sub-specialisation, and application of technology to clinical practice. It is an impossible task for non-imaging specialists to acquire and maintain the necessary breadth and depth of knowledge for confident and correct requesting decisions.

When surveyed, clinicians expressed a need for guidelines to support their selection of diagnostic imaging procedures. The development and deployment of decision support systems has been suggested as a specific strategy to increase the appropriateness of diagnostic testing 2, 10.

Guidelines, algorithms and practice recommendations are instruments for a structured approach to medical decision and for making medical care more consistent and efficient 11. Clinical guidelines are defined as “systematically developed statements to assist practitioner and patient decisions about appropriate health care for specific clinical circumstances” 12. Algorithms, defined as “systematic processes consisting of an ordered sequence of steps with each of them depending on the outcome of the

4 previous”, have the advantage of precisely formulated iterative thought processes which can be applied in clinical medicine for structured protocols for medical decisions 11, 13-15.

To improve referral practices, the Royal Australian and New Zealand College of Radiologists (RANZCR) published a set of “Imaging Guidelines”, currently in the fourth revision 16. The guidelines are intended as decision support tool for medical practitioners in their selection of diagnostic imaging procedures. These guidelines have been criticised for being too simplistic. In particular, they often fail to address sets of symptom complexes enabling clinicians to choose the most optimal sequence of imaging examinations in reaching a diagnosis. Moreover, the print copies of these guidelines were simply mailed out to the medical practitioners. The mode of dissemination is important to ensure utilisation of imaging guidelines 17-19. Passive dissemination of imaging guidelines has been found to be ineffective if used alone and additional dissemination and implementation strategies are felt to be necessary to promote the use of imaging guidelines 17-19.

Furthermore, there is a lack of consensus among imaging specialists about the optimum diagnostic imaging pathways and the best way of presenting pathways as a decision support tool for medical practitioners. There is a need to develop a suite of imaging pathways based on expert judgment, has broad consensus, is backed by clinical evidence wherever possible, and is structured and presented as a tool to assist clinical decision making.

In view of perceived limitations of existing guidelines, a group of Imaging Specialists and referring clinicians at Royal Perth Hospital applying their expert judgment, developed a set of ‘Diagnostic Imaging Pathways’ 20. In 1992, Imaging Specialists at Royal Perth Hospital (RPH) developed pathways for diagnostic testing, and a document was made available to assist hospital-based requesting clinicians (especially junior doctors) in their choice of appropriate examinations for common presenting conditions. The pathways suggest imaging strategies for many of the more frequently occurring clinical problems. They are intended as a guide for medical practitioners presented with clinical symptoms and signs, to choose an appropriate sequence of examinations. However, these guidelines did not provide any supporting evidence for the diagnostic imaging pathways.

5 During subsequent revisions of the pathways, it became increasingly apparent that there was a need to close the gap between evidence and clinical practice relating to diagnostic imaging, and to develop an appropriate electronic environment to facilitate dissemination and continuous updating of the pathways.

Current best medical practice encourages that as far as possible we should base our medical decisions on practices/treatments which have been clinically proven using the scientific method. Consensus and evidence-based diagnostic imaging guidelines/pathways would strengthen the confidence of clinicians in their attempt to make the right decision 11, 21. The increasing appropriateness of examinations will improve the quality of health care, through reduced unnecessary radiation exposure, reduced exposure to risks associated with invasive examinations and ultimately increasing the effectiveness of diagnostic services 22-25. It would lead to reduced costs by reducing unnecessary imaging examinations.

In an environment of ‘information overload’ it is always difficult to bring attention to an initiative and gain its acceptance, especially if the objective is to change patterns of behaviour. There is need to raise state-wide awareness among medical practitioners, of the availability of a suite of imaging pathways as a tool in clinical decision making, and to clarify the benefits to patient care of using this tool in their own practice, quoting evidence wherever possible. Benefits will include improved diagnostic effectiveness, and reduced exposure to risks associated with any invasive diagnostic procedure 22-25.

Against this background, one strategy is to develop, disseminate, implement and evaluate diagnostic imaging pathways (DIP), to inform and guide requestors and providers of diagnostic imaging to achieve the appropriate application of medical imaging technology to diagnosis.

6 HYPOTHESIS

There is deficiency in the evidence base and scientific underpinning of existing diagnostic imaging algorithms for diagnostic endpoints.

AIMS 1. To carry out a systematic review of literature in relation to use of diagnostic imaging tests in diagnosis and evaluation of 78 common clinical problems. 2. To identify deficiencies and controversies in existing diagnostic imaging algorithms. 3. To develop a new set of consensus based diagnostic imaging pathways (DIP) supported by evidence, as an education and decision support tool for hospital based doctors and general practitioners in the Western Australia. 4. To carry out a trial dissemination, implementation and evaluation.

The following are the four main steps in the development of the diagnostic imaging pathways: 1. Clinical and academic content 2. Medium of distribution - electronic environment 3. Dissemination and implementation 4. Evaluation and Feedback

Each of the above four aspects involved in the process of the development of the diagnostic imaging pathways has been discussed under a separate heading in this thesis. The methodologies for dissemination and implementation are described for each step. The outcome of a small scale trial is reported in terms of the acceptance of DIP and the impact on knowledge of diagnostic imaging and requesting practice. Barriers to implementation are described and future directions outlined.

My main contribution is to the “clinical and academic content” step in the development of the Diagnostic Imaging Pathways with further intellectual contributions to the design of medium of distribution, dissemination and implementation and trial evaluation phases.

7

Chapter 2

Clinical and Academic content

8 CLINICAL AND ACADEMIC CONTENT

OBJECTIVE a) To carry out a systematic review of literature in relation to use of diagnostic imaging tests in diagnosis and evaluation of 78 common clinical topics. b) To identify deficiencies and controversies in existing diagnostic imaging algorithms. c) To develop a new set of consensus based diagnostic imaging pathways (DIP) supported by evidence, as an education and decision support tool for hospital based doctors and general practitioners in the Western Australia.

METHODOLOGY Starting with previous editions, a range of topics were reviewed. 78 common clinical topics were chosen for development of Diagnostic Imaging Pathways. While only one product was to be developed, the needs of differing groups of users were taken into account. For general practitioners, the topics considered met the following criteria: • Common clinical problem (eg chronic headache, hypertension). • Complex in regard to options available for imaging in the general practitioner setting (eg dyspepsia). • Subject to inappropriate imaging in the opinion of the Editors, resulting in 'unnecessary' expenditure and/or radiation exposure (eg plain x-rays for lower back pain). • New options for imaging which, in the opinion of the Editors, general practitioners may not be aware eg multidetector CT and application of magnetic resonance imaging/MRI (even though Australian general practitioners cannot not refer for MRI, this diagnostic modality was included in the pathways as an indicator for referral to appropriate specialist).

For hospital-based junior doctors and medical students, additional criteria included: • Acute presentations where immediate access to expert radiological opinion may be lacking (eg aspects of the 'acute abdomen'). • Clinical problem for which, in the opinion of the Editors, there is a need for education (eg renal colic, imaging of pancreatitis).

9 I carried out systematic review of literature for each of the 78 topics using Ovid, Pubmed 26 and Cochrane Database of Systematic Reviews 27. The evidence, thus, gathered was graded using the Oxford Centre of Evidence-Based Medicine Levels of evidence 28. The earlier editions of diagnostic imaging algorithms were recalled, the deficiencies and controversies were identified. An updated, modified or a new draft pathway was created based on evidence. The evidence supporting the pathway was presented in the form of text dot points together with the references for each topic. Where nationally or internationally published and accepted guidelines were available (eg Ottawa rules of ankle injury 29), this information was coalesced into a draft pathway. The draft pathways were initially provided to the editors of DIP project (Dr Richard Mendelson and Dr Martin Blake) and followed by appropriate subspecialty imaging consultants and specialist clinicians. The draft pathways relating to general practice were provided to general practitioners nominated by the Royal Australian College of General Practitioners. The opinions and suggestions received led to revisions based on consensus and draft of additional pathways as appropriate. For selected topics, draft guidelines were presented at joint clinico-radiological meetings, and feedback received was incorporated into the pathways and a “final draft” was produced based on consensus opinion. If consensus opinion could not be reached, or if the literature did not provide good evidence, it was indicated in notes to a pathway.

RESULTS Topics for which diagnostic imaging pathways have been developed were chosen as much as possible from a 'symptom complex' point of view; i.e. how patients present in a ward, clinic or general practice (eg 'dyspepsia' rather than 'investigation of possible peptic ulcer'). The pathways are based on the consensus opinion of imaging specialists, hospital based clinicians and general practitioners, and are supported by the best available published evidence. A total of 78 pathways were developed covering all organ systems (except breast imaging), grouped according to human systems (gastrointestinal, central nervous system, musculoskeletal, cardiovascular, respiratory, endocrine, genito-urinary, ear/nose/throat, obstetrics and gynaecology), and prepared for common presenting symptoms (eg chronic headache, shoulder pain, lower urinary tract symptoms) and preliminary diagnoses (eg suspected ectopic pregnancy, intra-abdominal abscess). DIP is currently limited to adults. The majority of topics are presented as a flow-chart, with notes on imaging procedures and references quoting the level of evidence. Other content and features include:

10 • A user guide (notes on web-browser compatibility, instructions on navigation). • An overview section (general statement on the purpose of DIP, general principles regarding the requesting of medical imaging examinations, explanation of levels of evidence, introduction to common imaging modalities). • Statement about biological effects and risks of ionising radiation.

Areas of unresolved controversy are acknowledged in the text with reference to current expert opinion and possible alternative options. The non-availability of diagnostic modalities in particular circumstances is acknowledged (eg general practitioners in Australia may not refer patients for MRI), but were purposely included in pathways as an indicator for referral to appropriate specialists.

I have made the major contribution to the clinical and academic content of the diagnostic imaging pathways. The text presented in the form of evidence supporting the algorithms in the diagnostic imaging pathways is my original work with input from the editors of DIP project. There was difficulty in grading the evidence as there is paucity of systemic review on diagnostic imaging examinations. The majority of evidence broadly falls into Level II and III as per Oxford Centre for Evidence-Based Medicine Levels of Evidence 26. These imaging pathways are based on the best available evidence, not necessarily of Level I quality. The scientific statistics such as sensitivity, specificity, positive and negative predictive values have been included, where appropriate, to justify why one imaging modality has been chosen over other. The following are the developed final consensus based diagnostic imaging pathways supported by evidence, with each symptom complex presented and discussed under separate headings.

11

DIAGNOSTIC IMAGING PATHWAYS

12

ABDOMINAL (AAA)

ULTRASONOGRAPHY (US) • Most aneurysms are detected by ultrasound as an incidental finding for symptoms related to other pathology or physical examination. 4 • Physical examination has only moderate overall sensitivity (68%) for the detection of abdominal aortic aneurysms (AAA) but is highly sensitive for diagnosis of AAAs large enough to warrant elective intervention in patients who do not have a large girth. 5 • Ultrasound is highly accurate in detecting the presence or absence of abdominal aortic aneurysms. 6 • Surveillance of abdominal aortic aneurysms less than 5.5cm in diameter has been reported to be safe and survival is not improved by elective repair of abdominal aortic aneurysms compared to surveillance of this group. 7,8 • Surveillance with vigilant clinical evaluation and radiographic imaging is indicated in patients with abdominal aortic aneurysm between 4.0 to 5.4 cm in diameter. 7,8 • Small abdominal aortic aneurysms between 3.0-3.9cm in diameter expand slowly (median of 2mm per annum), rarely rupture or expand to more than 5.0cm but still can be life threatening in some patients. Hence, less frequent surveillance is recommended. 1, 9-11

13 REFERENCES 1. Ebaugh JL, Garcia ND, Matsumura JS. Screening and surveillance for abdominal aortic aneurysms: who needs it and when. Seminars in 2001; 14(3): 193-199. 2. UK Small Aneurysm Trial Participants: The UK Small Aneurysm Trial: Design, methods and progress. Eur J Vasc Endovasc Surg 1995; 9: 42-48. 3. Lederle FA, Wilson SE, Johnson GR, et al. Design of the abdominal aneurysm detection and management study. J Vasc Surg 1994; 20: 296-303. 4. The Multicentre Aneurysm Screening Study Group. The Multicentre Aneurysm Screening Study (MASS) into the effect of abdominal aortic aneurysm screening on mortality in men: a randomised controlled trial. Lancet 2002; 360: 1531-1539. (Randomised controlled trial 27,147 participants – Level I evidence) 5. Fink HA, Ledele FA, Roth CS, et al. The accuracy of physical examination to detect abdominal aortic aneurysm. Arch Intern Med 2000; 160: 833-836. (Prospective study cohort of 200 patients – Level III evidence) 6. Kuhn M, Bonnin RLL, Davey MJ, et al. Emergency department ultrasound scanning for abdominal aortic aneurysm: accessible, accurate, and advantageous. Ann Emerg Med 2000; 36: 219-223. (Prospective study 68 US scans – Level II evidence) 7. Lederle FA, Wilson SE, Johnson GR, et al. ADAM study. Immediate repair compared with surveillance of small abdominal aortic aneurysms. NEJM 2002; 346(19): 1437-1444. (Prospective randomised controlled trial 1136 male patients with 4.0-5.4cm AAA – Level I evidence) 8. The United Kingdom Small Aneurysm Trial Committee. Long term outcomes of immediate repair compared with surveillance of small abdominal aortic aneurysms. NEJM 2002; 346: 1445-1452. (Prospective randomised controlled trial 1090 patients with 4.0-5.5cm AAA – Level I evidence) 9. Biancari F, Mosorin M, Anttila V, et al. Ten-year outcome of patients with very small abdominal aortic aneurysm, Am J Surg 2002; 183: 53-55. (Retrospective study cohort of 41 patients with 2.5-4.0 cm AAA – Level III evidence) 10. Stantilli SM, Littooy FN, Cambria RA, et al. Expansion rates and outcomes for the 3.0-cm to the 3.9-cm infrarenal abdominal aortic aneurysm. J Vasc Surg 2002; 35: 666-671. (Prospective observational study 790 patients – Level II evidence) 11. Vardulaki KA, Presvost TC, Walker NM, et al. Growth rates and risk of rupture of abdominal aortic aneurysms. Br J Surg 1998; 85: 1674-1680. (Level II evidence)

14 BLUNT TRAUMATIC INJURY OF THORACIC AORTA

BLUNT TRAUMATIC INJURY OF THORACIC AORTA • Mechanism of : sudden deceleration or crush injuries to the chest causing shearing or bending forces to thoracic aorta. 1-4 • Majority are fatal at the scene of the accident. Prompt diagnosis and treatment are essential on admission in survivors. 1-4 • >90% of injuries occur at the aortic isthmus. Most of the rest occur in proximal ascending aorta. 1-4 • Prompt diagnosis depends on the level of clinical suspicion (mechanism of injury) and imaging. 1-4

PLAIN • Initial screening study for evaluation of blunt thoracic trauma. 1-5 • Supine chest radiography has 90% sensitivity, 25% specificity and a 96% negative predictive value for the detection of mediastinal haematoma. 5,6 • Radiographic findings in traumatic aortic rupture include: 1,5 1. Features directly related to the aortic injury: irregularity or blurring of the aortic knob contour, aortic knob enlargement.

15 2. Features related to the presence of a mediastinal haematoma: mediastinal widening, obscuration of aortic arch margin, deviation of to the right, deviation of nasogastric tube to the right, depressed left main , loss of aorto-pulmonary window, widening of paraspinal stripes. 3. Other features: left apical cap, left haemothorax. • Most of the findings in aortic rupture are related to mediastinal haematoma rather to the aortic injury itself. 1 • Plain chest radiographs (and particularly supine CXR) show low specificity for detection of thoracic aortic injuries. 5 • A combination of signs is more reliable than a single sign, but all are relatively non- specific. 5 • Evaluation of serial chest radiographs following trauma is an acceptable alternative to in the few chest trauma patients with no clinical or radiographic suspicion of vascular injury. 6

COMPUTED • Contrast-enhanced spiral CT has high (>96%) sensitivity and specificity for detecting mediastinal haemorrhage and assessing the abnormalities related to thoracic aortic injuries (intimal flaps, pseudotumours, intraluminal thrombi, contour anomalies, pseudocoarctation of the aorta, contrast material extravasation). 7-10 • Allows of stable patients and prevents unnecessary aortography. 8,10 • No further imaging is indicated in patients in whom there is no evidence of periaortic mediastinal haematoma or direct signs of aortic injury. 10 • Indications: 1. Clinically stable patients with negative chest radiographs in whom the mechanism of injury or other clinical signs raise the possibility of aortic laceration. Aortography is performed if the CT is positive for blood in the periaortic, middle, or superior mediastinal regions. If the CT is negative, the patient may be followed with serial chest films. 1-3 2. Clinically stable patients in whom suboptimal or equivocal chest radiographs fail to exclude mediastinal haematoma should have an erect posteroanterior radiograph. If the radiograph is abnormal, CT should be performed. If mediastinal blood or aortic contour abnormality is present, Aortography is indicated. 4,7,11 • The location of the haematoma is significant, since a haematoma confined to the retrosternal area is of doubtful significance, whereas a para-aortic haematoma or one around the branches of the arch are significant and require further investigation. 12 • Post-IV-contrast CT may show direct signs of aortic injury. 7,8 • Advantages: • Fast, non-invasive, safe test. • Less expensive compared to aortography. • Ability to distinguish mediastinal blood from other causes of mediastinal widening detected on initial chest radiographs eg artifacts of magnification, mediastinal fat, or anatomical variation. • Limitations: • Motion artifacts. • Artifacts caused by nasogastric and endotracheal tubes obscuring intimal defects of aorta.

16 TRANSOESOPHAGEAL ECHOSONOGRAPHY (TOE) • There is no consensus regarding the role of transoesophageal echosonography in the evaluation of chest trauma patients with suspected thoracic aortic injuries. 2,13 • Initial studies have reported high accuracy in expert hands. 2,14,15 • Advantages: can be performed at the patient bedside. • Limitations: 2,13 • There may be blind areas of the aorta and branch vessels in some patients. • Limited availability. • Disadvantages: semi-invasive procedure requiring sedation.

AORTOGRAPHY • “Gold standard” in diagnosing acute traumatic aortic injuries. 1-4 • Useful for establishing the diagnosis, defining the anatomy of the lesion, and identifying additional sites of injury. 1-4 • Indicated in: 1,3,4,10 • All clinically unstable patients suspected of having traumatic aortic injury. • Clinically stable patients with an evidence of significant mediastinal haematoma or direct signs of aortic injury on CT. • Allows complete evaluation of the thoracic aorta from the aortic root to the diaphragmatic hiatus and the brachiocephalic and their branches. 2,16 • Disadvantages: • Invasive procedure with a risk of complications. • Use of material. • Time consuming.

17 REFERENCES 1. Wintermark M, Wicky S, Schnyder P. Imaging of acute traumatic injuries of the thoracic aorta. Eur Radiol 2002; 12: 431-442. (Review) 2. Patel NH, Stephens KE, Mirvis SE, et al. Imaging of acute thoracic aortic injury due to : a review. Radiology 1998; 209: 335-348. (Review) 3. Fishman JE. Imaging of blunt aortic and great vessel trauma. J Thoracic Imaging 2000; 15: 97-103. 4. Zinck SE, Primack SL. Radiographic and CT findings in blunt chest trauma. J Thoracic Imaging 2000; 15: 87-96. 5. Mirvis SE, Bidwell JK, Buddemeyer EU. Value of chest radiography in excluding traumatic aortic rupture. Radiology 1987; 163: 487-493. (Retrospective study cohort of 205 patients – Level III evidence) 6. Woodring JH. The normal in blunt traumatic rupture of the thoracic aorta and brachiocephalic arteries. J Emerg Med 1990; 8: 467-476. (Review of 656 patients from 52 studies – Level II/III evidence) 7. Mirvis SE, Shanmuganathan K, Miller BH, et al. Traumatic aortic injury: diagnosis with contrast enhanced thoracic CT: 5-year experience at a center. Radiology 1996; 200: 413-422. (Meta-analysis of 3334 patients from 19 studies – Level II evidence) 8. Scaglione M, Pinto A, Pinto F, et al. Role of contrast-enhanced helical CT in the evaluation of acute thoracic aortic injuries after blunt chest trauma. Eur Radiology 2001; 11: 2444-2448. (Retrospective study cohort of 1419 consecutive patients – Level II evidence) 9. Gavant ML, Mezel PG, Fabian T, et al. Blunt traumatic aortic rupture: detection with Helical CT of the chest. Radiology 1995; 197: 125-133. (Prospective study 1518 consecutive patients – Level II evidence) 10. Dyer DS, Moore EE, Mestek MF, et al. Can chest CT be used to exclude aortic injury? Radiology 1999; 213: 195-202. (Retrospective study 383 patients – Level III evidence) 11. Richardson P, Mirvis SE, Scorpio R, et al. Value of CT in determining the need for when findings of mediastinal hematoma on chest radiographs are equivocal. AJR 1991; 156: 273-279. (Prospective study cohort of 90 patients – Level II/III evidence) 12. Wong YC, Wang LJ, Lim KE, et al. Periaortic hematoma on helical CT of the chest: a criterion for predicting blunt thoracic aortic rupture. AJR 1998; 170:1523-1525. (Retrospective study 21 patients – Level III evidence) 13. Willens HJ, Kessler KM. Transoesphageal in the diagnosis of diseases of the thoracic aorta: Part II – atherosclerotic and traumatic diseases of the aorta. Chest 2000; 117: 233-243. (Review) 14. Goarin JP, Caloire P, Jacquens Y, et al. Use of transoesophageal echocardiography for diagnosis of traumatic aortic injury. Chest 1997; 112: 71-80. (Prospective study 28 patients with traumatic aortic injury + 30 controls – Level III evidence) 15. Vignon P, Gueret P, Vedrinne J-M, et al. Role of transoesophageal echocardiography in the diagnosis and management of traumatic aortic disruption. Circulation 1995; 92: 2959-2968. (Prospective study 32 consecutive patients – Level II/III evidence) 16. Ahrar K, Smith DC, Bansal RC, et al. Angiography in blunt thoracic aortic injury. J Trauma 1997; 42: 665-669. (Retrospective study 89 patients – Level III evidence)

18 SUSPECTED FIRST LOWER LIMB DEEP VENOUS THROMBOSIS

SUSPECTED • Clinical pretest probability identifies high-risk individuals in whom a more aggressive diagnostic approach may be indicated and low-risk individuals in whom minimal diagnostic testing needs to be performed. 1,2

ULTRASOUND • Most accurate non-invasive test for the diagnosis of a first symptomatic proximal deep vein thrombosis (>95% sensitivity and specificity). 3,4 • The inability to completely compress the vein lumen is the principal criterion for the diagnosis of deep vein thrombosis. 5 • A negative single ultrasound result in patients with low clinical pretest probability, excludes the diagnosis of deep vein thrombosis. 1 • When US is negative in patients with suspected deep vein thrombosis, serial US can be used to detect proximal extension of calf deep vein thrombosis in symptomatic outpatients. 4,6 However, a recently published level II study questions the value of routine second scanning at one week. 7 • Anticoagulant treatment can be safely withheld in outpatients with low or moderate clinical pre-test probability of deep vein thrombosis after single or repeated negative US, respectively. 1,8 • Advantages: 5 • Ability to depict anatomical variants (eg duplicated venous segments) and alternative causes of symptoms. • Can be performed in critically ill patients. • Non-invasive. • No exposure to ionising radiation. 19 • Does not involve the use of . • Relatively inexpensive. • Limitations: 4 • Reduced predictive value if the results are discordant with the clinical assessment of pretest probability. Therefore, should be performed if the ultrasound result and clinical pretest probability are discordant. 9 • Venous compressibility may be limited by patient characteristics such as obesity, oedema, and tenderness. • False positives may occur due to extrinsic compression of a vein by pelvic mass or other perivascular pathology. • Unreliable in detecting deep vein thrombosis in iliac .

VENOGRAPHY • “Gold standard” for the diagnosis of deep vein thrombosis. 3,4 • Use limited to cases where non-invasive test results are non-diagnostic or discordant with the clinical assessment of pretest probability. 3,4 • Disadvantages: invasive, requires contrast media, exposure to ionising radiation and difficult to perform in critically ill patients.

20 REFERENCES 1. Wells PS, Anderson DR, Bormanis J, et al. Value of assessment of pretest probability of deep-vein thrombosis in clinical management. Lancet 1997; 350: 1795-1798. (Prospective study cohort of 593 consecutive outpatients – Level II evidence) 2. Perrier A, Desmarais S, Miron M-J, et al. Non invasive diagnosis of venous thromboembolism in outpatients. Lancet 1999; 353: 190-195. (Prospective study 918 consecutive patients – Level II evidence) 3. Kearon C, Julian JA, Math M, et al. Noninvasive diagnosis of deep venous thrombosis. Ann Intern Med 1998; 128: 663-677. (Review – Level II evidence) 4. American Thoracic Society. The diagnostic approach to acute venous thromboembolism: clinical practice guidelines. Am J Respir Crit Care Med 1999; 160: 1043-1066. 5. Fraser JD, Anderson DR. Deep venous thrombosis: recent advances and optimal investigation with US. Radiology 1999; 211:9-24. 6. Gottlieb RH, Wijaja J. Clinical outcomes of untreated symptomatic patients with negative findings on sonography of the thigh for deep vein thrombosis: our experience and a review of the literature. AJR 1999; 172: 1601-1604. (Retrospective study 146 patients – Level II/III evidence) 7. Friera A, Gimenez NR, Caballero P, et al. Deep vein thrombosis: can a second sonographic examination be avoided? AJR 2002; 178: 1001-1005. (Prospective study 438 consecutive patients – Level II evidence) 8. Cogo A, Lensing AWA, Koopman MMW, et al. Compression ultrasonography for diagnostic management of patients with clinically suspected deep vein thrombosis: prospective cohort study. BMJ 1998; 316: 17-20. (Prospective cohort study 1702 patients – Level II evidence) 9. Wells PS, Hirsch J, Anderson DR, et al. Accuracy of clinical assessment of deep- vein thrombosis. Lancet 1995; 345: 1326-1330. (Prospective study 529 patients – Level II evidence)

Further Reading 1. Gottlieb RH, Voci SL, Syed L, et al. Randomized prospective study comparing routine versus selective use of sonography of the complete calf in patients with suspected deep venous thrombosis. AJR 2003; 180: 241-245.

21 INVESTIGATION OF HYPERTENSION FOR RENOVASCULAR CAUSE

HIGH CLINICAL PROBABILITY • Consider renovascular hypertension when: 14 • Newly diagnosed hypertension presents with features that are atypical of essential hypertension such as young or very old patients, no family history, severely elevated blood pressure, epigastric bruit or coexisting clinical indicators of atherosclerosis (ie ischaemic heart, cerebral or peripheral vascular disease); or • Resistant hypertension is associated with risk factors for atheroma; or • Angiotensin-converting enzyme (ACE) inhibitor or angiotensin-II- receptor antagonist therapy is associated with increasing plasma creatinine levels.

22 COLOUR DOPPLER ULTRASOUND • Best screening tool for renovascular hypertension. 1, 2 • Ultrasound assesses renal size and morphology and Doppler gives information regarding blood flow velocities and waveform. • 63-100% sensitivity and 73-100% specificity for renal stenosis. 3 • A renal resistive index value of at least 80 reliably identifies patients with renal- artery stenosis in whom or surgery will not improve renal function, blood pressure, or kidney survival. 4 • Patients with abnormal US or high clinical suspicion of renal artery stenosis need to be further evaluated with MRA or CTA. 5,6 • Advantages: non-invasive, relatively inexpensive, does not involve the use contrast material and no exposure to ionising radiation. • Limitations: difficult in obese patients and where breath holding and cooperation are poor. 7

CAPTOPRIL RENAL SCAN • Assesses perfusion, function, transit time and response to captopril. • Currently used to determine functional significance of detected renal artery stenosis. • Inferior to other imaging modalities as a diagnostic test for renal artery stenosis. 3 • Sensitivity of 64-93% and specificity of 71-97% for renal artery stenosis when angiography used as standard of reference. 3 • Limitations: • False negative studies due to poor absorption of oral captopril. 7 • False positives due to stenosis proximal or distal to the main renal artery. 7

GADOLINIUM MAGNETIC RESONANCE ANGIOGRAPHY (MRA) • Most accurate non-invasive modality for detecting renal artery stenosis (>95% sensitivity and specificity). 3,8 • Useful in patients with impaired renal function. • Advantages : 7 • No risk of nephrotoxicity with gadolinium based contrast. • No radiation. • Combined with other MR techniques can assess the significance of stenosis • Can differentiate between truncal and ostial stenosis. • Disadvantages: not sensitive for distal artery or segmental renal artery stenosis (limited visualisation of intrarenal arteries). 7

SPIRAL CT ANGIOGRAPHY (CTA) • Alternative to gadolinium MRA. • ~95% sensitivity and specificity. 3 • Advantages: can identify non-renal causes of hypertension, and visualisation of both the arterial lumen and wall allows improved differentiation between truncal and ostial stenosis. 7 • Disadvantages: ionising radiation, contrast nephrotoxicity, and failure to identify small arteries <2mm and accurately assess renal arteries beyond renal hilum. 7

ANGIOGRAPHY • “Gold standard” for detection of renal artery stenosis. 7 • Provides therapeutic opportunity.

23 • Disadvantages: invasive with a risk of complications, expensive, requires administration of iodinated contrast material and exposure to ionising radiation.

RENAL ARTERY ANGIOPLASTY AND STENTING • In contrast to initial observational studies, recent randomised trials demonstrate no significant difference in blood pressure control and renal function when invasive therapy was compared to medical therapy 9, 11. However these trials did not use which have been shown to be superior to angioplasty alone for ostial lesions. 10-12 • Non–ostial stenoses and fibromuscular hyperplasia can be treated by angioplasty alone. 13 • Disadvantages: significant rate of technical failure, restenosis (17%) and complications (11%). 10,13 • Surgery is reserved for exceptional cases or following failed angioplasty.

24 REFERENCES 1. Krumme B, Blum U, Schwertfeger E, et al. Diagnosis of renovascular disease by intra- and extrarenal doppler scanning. Kidney Int 1996; 50: 1288-1292. (Prospective study 135 consecutive patients – Level II/III evidence) 2. Radermacher J, Brunkhorst R. Diagnosis and treatment of renovascular stenosis – a cost-benefit analysis. Nephro Dial Transplant 1998; 13: 2761-2767. 3. Vasbinder GBC, Neelmans PJ, Kessels AGH, et al. Diagnostic tests for renal artery stenosis in patients suspected of having renovascular hypertension: a meta-analysis. Ann Intern Med 2001; 135: 401-411. (Meta-analysis – Level I/II evidence) 4. Radermacher J, Chavan A, Bleck J, et al. Use of to predict the outcome of therapy for renal-artery stenosis. NEJM 2001; 344: 410-417. (Prospective study 5950 patients – Level I/II evidence) 5. Krijnen P, Van Jaarsveld BC, Steyerberg EW, et al. A for renal artery stenosis. Ann Intern Med 1998; 129: 705-711. (Clinical decision rule – Level II evidence) 6. Pedersen EB. New tools in diagnosing renal artery stenosis. Kidney International 2000; 57: 2657-2677. 7. Rankin SC, Saunders AJS, Cook GJR, et al. Renovascular Disease. Clinical Radiology 2000; 55: 1-12. (Review) 8. Qanadli SD, Soulez G, Therasse E, et al. Detection of renal artery stenosis: prospective comparison of captopril-enhanced doppler sonography, captopril- enhanced , and MR Angiography. AJR 2001; 177: 1123-1129. ( Prospective study 41 patients – Level III evidence) 9. Van Jaarsveld BC, Krijnen P, Pieterman H, et al. The effect of balloon angioplasty on hypertension in atherosclerotic renal artery stenosis. NEJM 2000; 342: 1007- 1014. (Prospective randomised trial 106 patients – Level II evidence) 10. Leertouwer TC, Gussenhoven EJ, Bosch JL, et al. placement for renal arterial stenosis: where do we stand? A meta-analysis. Radiology 2000; 216: 78-85. (Meta- analysis – Level II evidence) 11. Weibull H, Bergqvist D, Bergentz S-E, et al. Percutaneous transluminal renal angioplasty versus surgical reconstruction of atherosclerotic renal artery stenosis: a prospective randomized study. J Vas Surg 1993; 18: 841-852. (Prospective randomised study 58 patients – Level II evidence) 12. Baumgarter I, von Aesch K, Do D-D, et al. Stent placement in ostial and nonostial atherosclerotic renal arterial stenoses: a prospective follow-up study. Radiology 2000; 216: 498-505. (Prospective study 163 consecutive patients – Level II evidence) 13. Ramsay LE, Waller PC. Blood pressure response to percutaneous transluminal angioplasty for renovascular hypertension: an overview of published series. Br Med J 1990; 300: 569-572. ( Level III evidence) 14. Parker SC, Hannah A, Brooks M, et al. Renal artery stenosis: a disease worth pursuing. MJA 2001; 175: 149-153. (Clinical update)

Further Reading 1. Lee H-Y, Grant EG. Sonography in renovascular hypertension. J Ultrasound Med 2002; 21: 431-441.

25 LOWER LIMB CLAUDICATION

LOWER LIMB CLAUDICATION • The diagnosis of peripheral arterial occlusive disease begins with an accurate history. 1 • Intermittent claudication must be differentiated from lower extremity pain occurring as a result of non-vascular aetiologies. 1 • Neurogenic causes, such as spinal stenosis, account for most of the non-vascular causes of lower extremity pain. 1 • Noninvasive diagnostic studies help determine the level of the disease, may unmask a haemodynamically significant stenosis, and are useful in follow-up. 1, 2 • Imaging studies are useful in defining the location and extent of vascular lesions before a percutaneous or surgical revascularisation procedure. 1 • Main limitation of diagnostic testing is that proving the presence of vascular disease does not necessarily exclude the possibility that symptoms are caused by neurological disease despite the presence of arterial lesions. 1

26 COLOUR DOPPLER ULTRASONOGRAPHY • 87% sensitivity and 95% specificity for aortoiliac and femoral arterial stenosis >50%. 3-5 • Helps confirm the clinical assessment and determine the level and severity of disease. 3, 4 • Limitations: does not provide road map equivalent to angiography.

MAGENTIC RESONANCE ANGIOGRAPHY • >95% sensitivity and specificity for evaluation of peripheral arterial disease of lower extremities. 5, 6 • Superior discriminatory power compared to duplex ultrasonography. 5 • Useful adjunct and planning tool for both catheter-directed and surgical intervention. 6 • Advantages: non-invasive and does not involve exposure to ionising radiation. • Limitations: limited availability and high expense.

CATHETER ANGIOGRAPHY • “Gold standard” test for defining the vascular lesion’s morphology as well as providing a “road-map” of the vascular system. 1 • If invasive therapy is indicated, catheter angiography is used for an accurate and complete assessment of the peripheral arteries to help choose the optimal type and technique of revascularisation procedure. 1 • Disadvantages: invasive procedure with a risk of morbidity and mortality. 7, 8

PLAIN RADIOGRAPHS OF LUMBAR SPINE • Demonstration of degenerative spondylolisthesis or lumbar scoliosis are features more likely to be associated with lumbar spinal stenosis. 10-12 • Limitations: lack specificity. 9 • The diagnosis of lumbar spinal stenosis can be confirmed with CT or MRI. 12

COMPUTED TOMOGRAPHY OF LUMBAR SPINE • Most cost-effective single test for establishing the diagnosis of lumbar spinal stenosis. 12 • Provides excellent osseous detail, especially in the region of the lateral recess. 12 • Can differentiate the disc and ligamentum flavum from the thecal sac. 12 • Can provide excellent visualisation of far lateral disc abnormalities that may coexist with stenosis of the . 12

27 REFERENCES 1. Ouriel K. Peripheral arterial disease. Lancet 2001; 358: 1257-1264. 2. Schmieder FA, Comerota AJ. Intermittent claudication: magnitude of the problem, patient evaluation, and therapeutic strategies. Am J Cardiol 2001; 87 (suppl): 3D- 13D. 3. Koelemay MJW, Den Hartog D, Prins MH, et al. Diagnosis of arterial disease of lower extremities with duplex ultrasonography. Br J Surg 1996; 83: 404-409. (Meta- analysis – Level II/III evidence) 4. De Vries SO, Hunink MG, Polak JF. Summary receiver operating characteristic curves as a technique for meta-analysis of the diagnostic performance of duplex ultrasonography in peripheral arterial disease. Acad Radiol 1996; 3: 361-369. (Review of 14 studies - Level II/III evidence) 5. Visser K, Hunink MGM. Peripheral arterial disease: gadolinium-enhanced MR angiography versus color-guided duplex US – a meta-analysis. Radiology 2000; 216: 67-77. (Meta analysis – Level II/III) 6. Koelemay MJW, Lijmer JG, Stoker J, et al. Magnetic resonance angiography for the evaluation of lower extremity arterial disease: a meta-analysis. JAMA 2001; 285: 1338-1345. (Meta-analysis – Level II/III evidence) 7. Egglin TK, O’Moore PV, Feinstein AR, et al. Complications of peripheral arteriography: a new system to identify patients at increased risk. J Vasc Surg 1995; 22: 787-794. (Prospective study 549 consecutive patients – Level II evidence) 8. Hessel SJ, Adams DF, Abrams HL. Complications of angiography. Radiology 1981; 138: 273-281. (Level II/III evidence) 9. Moreland LW, Lopez-Mendez A, Alarcon GS. Spinal stenosis: a comprehensive review of the literature. Semin Arthritis Rheum 1989; 19: 127-149. 10. Saiffudin A. The imaging of lumbar spinal stenosis. Clinical Radiology 2000; 55: 581-594. (Review) 11. Stiel Radu A, Menkes CJ. Update on lumbar spinal stenosis: retrospective study of 62 patients and review of the literature. Rev Rhum Engl Ed 1998; 65: 337-345. (Retrospective study cohort of 62 patients – Level III evidence) 12. Spivak JM. Degenerative lumbar spinal stenosis. J Bone Joint Surg (Am) 1998; 80- A: 1053-1066.

Further Reading 1. Alvarez JA, Hardy RH Jr. Lumbar spine stenosis: a common cause of back and leg pain. American Family Physician 1998; April 15. www.aafp.org/afp. 2. Comerota AJ. Endovascular and surgical revascularisation for patients with intermittent claudication. Am J Cardiol 2001; 87(suppl): 34D-43D.

28 SPONTANEOUS AORTIC DISSECTION

AORTIC DISSECTION • Stanford classification of aortic dissection: 1 • Type A dissection includes the ascending aorta. • Type B dissection does not involve the ascending aorta (ie. distal to left subclavian artery). • Type A dissections are usually surgical emergencies owing to the high risk of acute aortic regurgitation, occlusion of coronary arteries and pericardial rupture. 1

COMPUTED TOMOGRAPHY • Contrast enhanced spiral CT scan is the initial investigation of choice for evaluation of suspected spontaneous aortic dissection. 1 • Comparable accuracy to that of MRI and transoesophageal echocardiography (TOE) with sensitivity and specificity approaching 100%. 2-4 • Superior to TOE and MRI in the assessment of aortic arch vessel involvement. 2 • The diagnosis is based on the demonstration of an intimal flap, which separates the true from the false channel. Secondary findings include internal displacement of intimal calcifications, delayed enhancement of the false lumen and aortic widening. 1, 5 • Atypical forms of aortic dissection can also be recognised eg. intramural haematoma, penetrating atherosclerotic ulcer and atypical configurations of the intimal flap. 1, 6 • CT findings of: type A intramural haematoma, maximum thickness of haematoma, compression of true lumen, and pericardial or pleural effusion, can predict the progression of aortic intramural haematoma to aortic dissection. 7 • Advantages: 1, 3 • Non-invasive, rapid test. • Widely available. • Allows distinction of type A from type B aortic dissection.

29 • Allows imaging of the entire aorta and demonstrates the extent of involvement and organ ischaemia. • Permits follow-up of aortic dissection, aneurysm or intramural haematoma. • Limitations: 1, 3, 4 • Does not provide information regarding the coronary arteries or aortic valve. • Disadvantages: • Exposure to ionising radiation. • Use of iodinated contrast material.

TRANSOESOPHAGEAL ECHOCARDIOGRAPHY (TOE) • Comparable accuracy to that of CT for detection of aortic dissection. 2, 4, 8 • Advantages: 2, 4, 8 • Can be performed at the bedside of critically ill patients. • Allows functional cardiac assessment. • Permits detection of coronary artery involvement. • Limitations: 2, 4, 8 • Invasive. • Limited availability and/or expertise. • Obscuration of the proximal aortic arch by interference from air within the trachea. • Lack of visualisation of the abdominal aorta (the distal extent of the dissection may not be seen if it involves the abdominal aorta).

MAGNETIC RESONANCE IMAGING (MRI) • Comparable accuracy to that of CT and transoesophageal echocardiography. 2, 4 • Advantages: 2, 4 • Provides excellent visualisation of tear localisation, aortic regurgitation, side branch involvement and complications. • No exposure to ionising radiation. • Non-invasive. • Limitations: 2, 4 • Expensive. • Limited availability. • Long examination time. • Difficulty of monitoring haemodynamically unstable patients (limited access to the patient). • Contraindicated in patients with pacemakers/certain heart valve prostheses.

30 REFERENCES 1. Coulam CH, Rubin GD. Acute aortic abnormalities. Seminars in Roentgenology 2001; 36(2): 148-164. 2. Sommer T, Fehske W, Holzknecht N, et al. Aortic dissection: a comparative study of diagnosis with spiral CT, multiplanar transoesophageal echocardiography, and MR imaging. Radiology 1996; 199: 347-352. (Prospective study 49 patients – Level II/III evidence) 3. Oliver TB, Murchison JT, Reid JH, et al. Spiral CT in acute non-cardiac . Clinical Radiology 1999; 54: 38-45. (Retrospective study cohort of 70 patients – Level III evidence) 4. Nienaber CA, von Kodolitsch Y, Nicolas V, et al. The diagnosis of thoracic aortic dissection by noninvasive imaging procedures. NEJM 1993; 328(1): 1-9. (Prospective study 110 patients – Level II evidence) 5. Erbel R, Alfonso F, Boileau C, et al. Diagnosis and management of aortic dissection. Recommendations of the task force on aortic dissection, European Society of Cardiology. European Heart Journal 2001; 22: 1642-1681. 6. Williams MP, Farrow R. Atypical patterns in the CT diagnosis of aortic dissection. Clinical Radiology 1994; 49: 686-689. (Case studies – Level IV/V evidence) 7. Choi SH, Choi SJ, Kim JH, et al. Useful CT findings for predicting the progression of aortic intramural hematoma to overt aortic dissection. J Computer Assisted Tomography 2001; 25(2): 295-299. (Cohort of 29 patients – Level III evidence) 8. Keren A, Kim CB, Hu BS, et al. Accuracy of biplane and multiplane transoesophageal echocardiography in diagnosis of typical acute aortic dissection and intramural hematoma. J Am Coll Cardiol 1996; 28: 627-636. (Retrospective cohort of 112 consecutive patients – Level II evidence)

Further Reading 1. Sebastia C, Pallisa E, Quiroga S, et al. Aortic dissection: diagnosis and follow-up with helical CT. Radiographics 1999; 19: 45-60. 2. Ciagarroa JE, Isselbacher EM, DeSanctis RW, et al. Diagnostic imaging in the evaluation of suspected aortic dissection. NE

31 SUSPECTED ISCHAEMIC CHEST PAIN

SUSPECTED ISCHAEMIC CHEST PAIN • Imaging studies are used in the investigation of chest pain: 1. Diagnostically: - whether or not the chest pain is ischaemic in origin, or 2. Prognostically: - to define the amount of at risk myocardium. - to determine risk of ischaemic events.

PLAIN CHEST RADIOGRAPHY • Initial imaging test for screening patients with acute chest pain of suspected myocardial ischaemic origin. 1, 2

32 • Useful in excluding other causes of chest pain that may masquerade as a myocardial ischaemia such as , fractured ribs, pneumonia, etc. 1, 2

ACUTE REST MYOCARDIAL PERFUSION IMAGING (MPI) • Useful for diagnosing myocardial ischaemia in patients where the combination of history and ECG changes is unreliable or non-diagnostic. 3-5 • Acute rest technetium-99m Sestamibi myocardial perfusion imaging in patients with suspected acute coronary syndromes has a high negative predictive value (99-100%) for excluding myocardial infarction, as well as predicting the absence of future adverse cardiac events. 4-9

GATED MYOCARDIAL PERFUSION IMAGING (MPI) • Allows evaluation of myocardial perfusion and ventricular function. 3 • Thallium-201 and the technetium-99m based perfusion agents (Sestamibi and Tetrofosmin) are the isotopes commonly used in myocardial perfusion imaging. 3 • Indications for imaging after myocardial infarction include risk assessment, prognosis and assessment of therapy: 3 1. Determine infarct size. 2. Determine extent of at risk myocardium. 3. Presence/extent of stress-induced ischaemia or impaired coronary reserve. 4. Presence and extent of viable but ischaemic myocardium. 5. Resting right ventricular and left ventricular function. • Indications for radionuclide imaging in diagnosis, prognosis and assessment of therapy in patients with unstable angina include: 3 1. Identification of ischaemia in the distribution of the “culprit” lesion or in remote areas. 2. Identification of the severity/extent of ischaemia in patients with ongoing chest pain. 3. Identification of the severity/extent of disease in patients whose angina is satisfactorily stabilised with medical therapy. 10-11 4. Measurement of baseline left ventricular function. • Limitations: requires patient transport to the imaging suite.

DOBUTAMINE STRESS ECHOCARDIOGRAPHY • Allows assessment of myocardial viability and prediction of improvement of function after revascularisation. 12, 13 • Relies on showing contractile reserve in dysfunctional segments during the infusion of low-dose dobutamine.

POSITRON EMISSION TOMOGRAPHY (PET) • Allows viability assessment using imaging with fluorodeoxyglucose in combination with a perfusion agent. 14, 15 • Limitations: availability, expense, rarely performed as 24-hour thallium imaging only slightly less sensitive.

CORONARY ANGIOGRAPHY • “Gold standard” in making the definitive diagnosis of coronary arterial obstruction as the probable cause for the chest pain. • Disadvantages: invasive procedure with potential risks and complications.

33 REFERENCES 1. Buenger RE. Five thousand acute care/emergency department chest radiographs: comparison of requisitions with radiographic findings. J Emerg Med 1988; 6: 197- 202. (Retrospective study cohort of 5000 chest radiographs of acute emergency department patients – Level III evidence) 2. Templeton PA, McCallion WA, McKinney LA, et al. Chest pain in the accident and emergency department: is chest radiography worthwhile? Arch Emerg Med 1991; 8: 97-101. (Prospective double blind study 327 consecutive patients – Level II evidence) 3. Report of the American College of Cardiology/American Heart Association Task Force on Assessment of Diagnostic and Therapeutic Cardiovascular Procedures (Committee on Radionuclide Imaging), Developed in Collaboration with the American Society of Nuclear Cardiology. ACC/AHA task force report: Guidelines for clinical use of cardiac radionuclide imaging. JACC 1995; 25: 521-547. 4. Radensky PW, Hilton TC, Fulmer H, et al. Potential cost-effectiveness of initial myocardial perfusion imaging for assessment of emergency department patients with chest pain. Am J Cardiol 1997; 79: 595-599. (Level III evidence) 5. Wackers FJ Th, Brown KA, Heller GV, et al. American Society of Nuclear Cardiology position statement on radionuclide imaging in patients with suspected acute ischaemic syndromes in the emergency department or chest pain center. J Nucler Cardiology 2002; 9: 246-250. (Position statement) 6. Varetto T, Canatalupi D, Altieri A, et al. Emergency room technetium-99m sestamibi imaging to rule out acute myocardial ischemic events in patients with nondiagnostic electrocardiograms. J Am Coll Cardiol 1993; 22: 1804-1808. (Prospective study 64 consecutive patients with chest pain – Level II evidence) 7. Hilton TC, Thompson RC, Williams HJ, et al. Technetium-99m sestamibi myocardial perfusion imaging in the emergency room evaluation of chest pain. J Am Coll Cardiol 1994; 23: 1016-1022. (Cohort of 102 patients – Level II evidence) 8. Kontos MC, Jesse RL, Schmidt KL, et al. Value of acute rest sestamibi perfusion imaging for evaluation of patients admitted to the emergency department with chest pain. J Am Coll Cardiol 1997; 30: 976-982. 9. Swinburn JMA, Stubbs P, Soman P, et al. Rapid assessment of patients with non- ST- segment elevation acute chest pain: troponins, inflammatory markers, or perfusion imaging? J Nucl Cardiol 2002; 9: 491-499. (Prospective study 80 nonconsecutive patients – Level III evidence) 10. Stratmann D, Williams GA, Wittry MD, et al. Exercise technetium-99m sestamibi tomography for cardiac risk stratification of patients with stable chest pain. Circulation 1994; 89: 615-622. (Prospective study cohort of 548 consecutive patients – Level II/III evidence) 11. Stratmann HG, Younis LT, Kong B. Prognostic value of dipyridamole thallium-201 scintigraphy in patients with stable chest pain. Am Heart J 1992; 123: 317-323. (Cohort of 373 patients – Level III evidence) 12. Cornell JH, Bax JJ, Fioretti PM. Assessment of myocardial viability by dobutamine stress echocardiography. Curr Opin Cardiol 1996; 11: 621-626. 13. Bax JJ, Wijns W, Cornell JH, et al. Accuracy of currently available techniques for prediction of functional recovery after revascularisation in patients with left ventricular dysfunction due to chronic coronary artery disease: comparison of pooled data. J Am Coll Cardiol 1997; 30: 1451-1460. 14. Bax JJ, Patton JA, Poldermans D, et al. 18-fluorodeoxyglucose imaging with emission tomography and single photon emission computed tomography: cardiac applications. Seminars in Nuclear Medicine 2000; 30(4): 281-298.

34 15. Gerber BL, Ordoubadi FF, Wijns W, et al. Positron emission tomography using (18) F-fluoro-deoxyglucose and euglycaemic hyperinsulinaemic glucose clamp: optimal criteria for the prediction of recovery of post-ischaemic left ventricular dysfunction. Results from the European Community Concerted Action Multicenter study on use of (18)F- fluorodeoxyglucose positron emission tomography for the detection of myocardial viability. European Heart Journal 2001; 22: 1691-1701.

35 ACUTE ONSET SEVERE HEADACHE / SUSPECTED SUBARACHNOID HAEMORRHAGE (SAH)

COMPUTED TOMOGRAPHY • Imaging modality of choice for the investigation of acute onset headache. 1-3 • High (90%) sensitivity for subarachnoid haemorrhage (SAH) if performed within 24 hours of haemorrhage. 4-6 • Provides an estimate and extent of the haemorrhage, and allows recognition of associated intracerebral haemorrhage, intraventricular haemorrhage, and hydrocephalus. 4 • Normal CT does not exclude subarachnoid haemorrhage, meningitis or encephalitis. • Limitations: 7 • Loss of sensitivity with increasing time between onset of headache and . • False negative results in cases of small-volume bleeding. 4 • False negative results for blood with a haematocrit of less than 30%.

LUMBAR PUNCTURE/CSF ANALYSIS • Performed in cases of suspected SAH with negative, equivocal or technically inadequate CT. 5,6,8 • Can help to confirm or rule out haemorrhage, infection, tumour and disorders related to CSF hypertension or hypotension. 7

36 • If SAH is suspected, the must be performed at least 6, and preferably 12 hours after the onset of suspected SAH. 9 • CSF is examined for xanthochromia by means of inspection and spectrophotometry. 9 • If CT or lumbar puncture indicates the presence of SAH, angiogram is indicated to identify the cause. 1 • If the CT and lumbar puncture are both normal, no further investigations are indicated. 1,10,11 • Limitations: 7 • Invasive • Misinterpretation of “traumatic tap”

DIGITAL SUBTRACTION ANGIOGRAPHY (DSA) • “Gold standard” for the detection of ruptured intracranial aneurysms and depicting the cerebral vascular anatomy. 3,12 • Necessary first step in the endovascular management of intracranial aneurysms. • Highly sensitive for detection of small aneurysms, small arteriovenous malformations and dural vascular malformations. 12 • A repeat angiogram is indicated in patients with SAH and in whom initial angiography revealed no diagnostic findings. 1 • Advantages: offers therapeutic opportunity. • Disadvantages: invasive procedure with potential complications.

CT ANGIOGRAPHY (CTA) • Non-invasive imaging modality for demonstrating vascular anatomy, with ~90% accuracy for depiction of cerebral aneurysms in acute SAH. 12,13 • Experience with CTA is still in its early stages and most patients end up having digital subtraction angiography(DSA) for definite diagnosis and management decisions. However, some neurosurgeons are using 3D-CT angiography in place of DSA in the diagnosis of ruptured aneurysms and for defining vascular anatomy before surgery. 13-16 • Limitations: • Low sensitivity for small intracranial aneurysms (<3mm). 12 • Does not enable imaging of the entire cerebral vasculature. • Inferior spatial resolution compared to DSA. • Does not provide precise information about intracranial haemodynamics. • Does not offer therapeutic opportunity.

MAGNETIC RESONANCE IMAGING • Imaging modality of choice for the detection and characterisation of suspected intracranial and meningeal infections and their complications. 17 • Inferior to CT for the detection of acute SAH but more sensitive than CT in the subacute and chronic stages. 18-20 • Fluid-attenuation-inversion recovery (FLAIR) sequences improve sensitivity for detection of SAH. 18-20 • Limitations: • Expensive • Limited availability

37 REFERENCES 1. American College of Emergency Physicians. Clinical Policy: critical issues in the evaluation and management of patients presenting to the emergency department with acute headache. Ann Emerg Med 2002; 39: 108-122. 2. Field AG, Wang E. Evaluation of the nontraumatic headache: an evidence based approach. Emerg Med Clinics of North America 1999; 17(1): 127-152. 3. Mayberg MR, Batjer HH, dacey R, et al. Guidelines for the management of aneurysmal subarachnoid haemorrhage: a statement for healthcare professionals from a special writing group of the stroke council, American Heart Foundation. Stroke 1994; 25(11): 2315-2328. 4. Kassell NF, Torner JC, Haley EC Jr, et al. The international cooperative study on the timing of aneurysm surgery, part 1: overall management results. J Neurosurg 1990; 73: 18-36. (Prospective observational epidemiological survey – Level II evidence) 5. Van der Wee N, Rinkel GJ, Hasan D, et al. Detection of subarachnoid haemorrhage on early CT: is lumbar puncture still needed after a negative scan? J Neurol Neurosurg Psychiatry 1995; 58(3): 357-359. (Prospective study 175 consecutive patients – Level II evidence) 6. Morgenstern LB, Lun-Gonzales H, Huber JC Jr, et al. Worst headache and subarachnoid hemorrhage: Prospective, Modern computed tomography and spinal fluid analysis. Ann Emerg Med 1998; 32: 297-304. (Prospective study 107 patients – Level II evidence) 7. Edlow JA, Caplan LR. Avoiding pitfalls in the diagnosis of subarachnoid haemorrhage. NEJM 2000; 342: 29- 36. (Review) 8. Edlow JA, Wyer PC. How good is a negative cranial computed tomographic scan result in excluding subarachnoid haemorrhage? Ann Emerg Med 2000; 36: 507-516. (Evidence-based emergency medicine/clinical question) 9. Vermeulen M, van Gijn J. The diagnosis of subarachnoid haemorrhage. J Neurology, Neurosurg, and Psychiatry 1990; 53: 365-372. (Review) 10. Wijdicks EFM, Kerkhoff H, van Gijn J. Long-term follow-up of 71 patients with thunderclap headache mimicking subarachnoid haemorrhage. Lancet 1988 july 9; 2:68-70. (Cohort of 71 patients – Level II/III evidence) 11. Harling DW, Peatfield RC, van Hille PT, et al. Thunderclap headache: is it migraine? Cephalagia 1989; 9: 87-90. (Prospective study 49 patients – Level III evidence) 12. White PM, Wardlaw JM, Easton V. Can non-invasive imaging depict intracranial aneurysms? A systematic review. Radiology 2000; 217: 361-370. (Level II evidence) 13. Anderson GB, Steinke DE, Petruk KC, et al. Computed tomographic angiography versus digital subtraction angiography for the diagnosis and early treatment of intracranial aneurysms. 1999; 45(6): 1315-1320. (Prospective study 173 consecutive patients – Level II evidence) 14. Hashimoto H, Iida J, Hironaka Y, et al. Use of spiral computed tomography angiography in patients with subarachnoid haemorrhage in whom subtraction angiography did not reveal cerebral aneurysms. J Neurosurg 2000; 92(2): 278-283. (Prospective study 134 consecutive patients with SAH – Level II evidence) 15. Matsumoto M, Sato M, Nakano M, et al. Three-dimensional computerized tomography-guided surgery of acutely ruptured cerebral aneurysms. J Neurosurg 2001; 94: 718-727. (Prospective study 100 consecutive patients – Level II evidence) 16. Velthuis BK, van Leeuwen MS, Witkamp TD, et al. Surgical anatomy of the cerebral arteries in patients with subarachnoid hemorrhage: comparison of

38 computerized tomography angiography and digital subtraction angiography. J Neurosurg 2001; 95: 206-212. ( Prospective study 73 patients – Level III evidence) 17. Falcone S, Post MJD. Encephalitis, cerebritis, and brain abscess: pathophysiology and imaging findings. Neuroimaging clinics of North America 2000; 10(2): 333- 353. 18. Mitchell P, Wilkinson ID, Hoggard N, et al. Detection of subarachnoid haemorrhage with magnetic resonance imaging. J Neurol Neurosurg Psychiatry 2001; 70: 205- 211. (Prospective study 41 patients – Level III evidence) 19. Ogawa T, Inugami A, Shimosegawa E, et al. Subarachnoid hemorrhage: evaluation with MR imaging. Radiology 1993; 186: 345-351. (Prospective study 37 patients – Level III evidence) 20. Noguchi K, Ogawa T, Seto H, et al. Subacute and chronic subarachnoid hemorrhage: diagnosis with fluid-attenuated inversion-recovery MR imaging. Radiology 1997; 203: 257-262. (Prospective study 14 patients with SAH and 22 controls – Level III evidence)

39 CHRONIC HEADACHE

CLINICAL HISTORY AND EXAMINATION • A thorough history and examination are critical in the evaluation of patient with headache. 1 • The following red flags on clinical assessment are indications for neuroimaging patients with chronic headache: 1-4 1. Headache beginning after 50yrs of age 2. Sudden onset of headache 3. Headache increasing in frequency and severity 4. New-onset headache in patient with risk factors for cancer or immunodeficiency (eg HIV infection) 5,6 5. Headache with signs of systemic illness (fever, stiff neck, rash, drowsiness) 6. Focal neurological signs or symptoms of disease (other than typical aura) 7. Papilloedema 8. Headache subsequent to head trauma 9. Personality change, cognitive deficit, or memory loss 10. History of seizures • Clinically recognisable patterns of headache which include: 1. Typical migraine, muscle contraction and cluster headache do not normally require imaging. 1,7-9 40 2. Headaches resulting from cervico-vertebral causes may require imaging with plain cervical spine radiographs +/- cervical spine CT or MRI of head/cervical spine. 3. Facial/sinus pain is best investigated with coronal CT (see separate algorithm for chronic sinusitis). 4. Pain typical of trigeminal neuralgia should be investigated with MRI in preference to CT. 10 5. Temporal headache in patients >55 years associated with local tenderness should be investigated for temporal arteritis.

NEUROIMAGING IN CHRONIC HEADACHE U.S Headache Consortium practice guidelines make the following recommendations for neuroimaging: 11 • Routine screening with imaging (CT or MRI) is not warranted as imaging in unselected patients with chronic headache has a poor yield of potentially treatable disorders (<0.5%). 12-17 • Neuroimaging should be considered in patients with nonacute headache and unexplained abnormal finding on the neurological examination as there is high likelihood of intracranial pathology. 11 • Routine imaging is not indicated in patients with migraine and normal neurological examination unless they have a history of seizure or atypical headache or have focal neurological symptoms and/or signs. 7,12

COMPUTED TOMOGRAPHY (CT) • Where imaging is indicated, CT is the most appropriate screening imaging study.11

MAGNETIC RESONANCE IMAGING • More sensitive than CT for detection of white matter lesions and developmental venous anomalies (? uncertain clinical relevance). 8,18,19 • Indicated in suspected cerebral venous sinus thrombosis. 20

41 REFERENCES 1. Field AG, Wang E. Evaluation of the nontraumatic headache: an evidence based approach. Emerg Med Clinics of North America 1999; 17(1): 127-152. (Evidence-based review) 2. American College of Emergency Physicians. Clinical Policy: critical issues in the evaluation and management of patients presenting to the emergency department with acute headache. Ann Emerg Med 2002; 39: 108-122. 3. Clinch CR. Evaluation of acute headaches in adults. American Family Physician 2001; 63: 685-692. (Review) 4. Ramirez-Lassepas M , Espinosa CE, Cicero JJ, et al. Predictors of intracranial pathologic findings in patients who seek emergency care because of headache. Arch Neurol 1997; 54: 1506-1509. (Retrospective study 468 case controls – Level IV evidence) 5. Lipton RB, Feraru ER, Weiss G, et al. Headache in HIV-1 related disorders. Headache 1991; 31: 518-522. (Cohort of 49 consecutive patients – Level II/III evidence) 6. Rothman RE, Keyl PM, Mc Arthur JC, et al. A decision guideline for emergency department ultilization of noncontrast head computed tomography in HIV-infected patients. Acad Emerg Med 1999; 6: 1010-1019. (Prospective study 110 patients – Level II evidence) 7. Frishberg BM. The utility of neuroimaging in the evaluation of headache in patients with normal neurologic examinations. Neurology 1994; 44: 1191-1197. (Review – Level III evidence) 8. De Benedittis GD, Lorensetti A, Sina C, et al. Magnetic resonance imaging in migraine and tension-type headache. Headache 1995; 35: 264-268. (Cohort of 63 consecutive patients – Level III evidence) 9. Cooney BS, Grossman RI, Farber RE, et al. Frequency of magnetic resonance imaging abnormalities in patients with migraine. Headache 1996; 36: 616-621. (Cohort of 185 consecutive patients – Level III evidence) 10. Elias WJ, Burchiel KJ. Trigeminal neuralgia and other neuropathic pain syndromes of the head and face. Current Pain & Headache Reports 2002; 6(2): 115-124. (Review) 11. US Headache Consortium. Evidence-based guidelines in the primary care setting: neuroimaging in patients with nonacute headache. American Family Physician, 2000 (online). Available at: http://www.aafp.org/afp. (Evidence based guidelines) 12. Wang HZ, Simonson Tm, Greco WR, et al. Brain MR imaging in the evaluation of chronic headache in patients without other neurologic symptoms. Acad Radiology 2001; 8: 405-408. (Retrospective study cohort of 402 patients – Level III evidence) 13. Weingarten S, Kleinman M, Elperin L, et al. The effectiveness of cerebral imaging in the diagnosis of chronic headache. Arch Intern Med 1992; 152: 2457-2462. (Retrospective study cohort of 89 patients with chronic isolated headache who had CT – Level III evidence) 14. Dumas MD, Pexman JHW, Kreeft JH. Computed tomography evaluation of patients with chronic headache. CMAJ 1994; 151: 1447-1452. (Retrospective study 373 consecutive patients – Level III evidence) 15. Mitchell CS, Osborn RE, Grosskreutz SR, et al. Computed tomography in the headache patient: is routine evaluation really necessary? Headache 1993; 33: 82- 86. (Prospective study 35 patients – Level II evidence)

42 16. Akpek S, Arac M, Atilia S, et al. Cost-effectiveness of computed tomography in the evaluation of patients with headache. Headache 1995; 35: 228-230. (Retrospective study 529 patients – Level III evidence) 17. Osborn RE, Alder DC, Mitchell CS. MR imaging of the brain in patients with migraine headaches. AJNR 1991; 12: 521-524. (Prospective study 41 patients with migraine referred for MRI – Level III evidence) 18. Demaerel P, Boelaert I, Wilms G, et al. The role of computed tomography in the diagnostic work-up of headache. Headache 1996; 36: 347-348. (Retrospective study cohort of 363 consecutive patients – Level III evidence) 19. Kuhn MJ, Shekar PC. A comparative study of magnetic resonance imaging and computed tomography in the evaluation of migraine. Computed Med Imaging Graph 1990; 14(2): 149-152. (Cohort of 74 consecutive patients with classic migraine – Level III evidence) 20. Allroggen H, Abbott RJ. Cerebral venous sinus thrombosis. Postgrad Med J 2000; 76: 12-15. (Review)

43 SUSPECTED NON-TRAUMATIC CORD COMPRESSION

PLAIN RADIOGRAPHY OF THE SPINE • Initial screening test for the evaluation of suspected compression. 1 • Common findings are pedicular erosion, vertebral collapse, pathological fracture dislocation, and soft tissue shadows suggesting a paraspinal mass. • Focal radiographic abnormalities with consistent neurological findings, when present, can accurately predict the presence and level of metastatic malignant spinal cord compression. However, whole spine MRI is indicated in most patients with suspected metastatic malignant spinal cord compression because the additional information may alter the management plan. 1, 2 • Treatment may be appropriately initiated on the basis of focal radiographic changes and consistent neurology if MRI is contraindicated or delayed, and in patients with a poor prognosis. 1 • In patients in whom focal plain radiographic and consistent clinical findings are absent, urgent spinal cord imaging with MRI is indicated before treatment is commenced. 1

MAGNETIC RESONANCE IMAGING (MRI) • Imaging modality of choice for diagnosis of metastatic malignant spinal cord compression. 1-7 • Advantages: • Demonstrates the level and the extent of cord compression (~95% accuracy) and influences the treatment decisions. 2, 4, 6 • Determines whether the major component of compression is due to bone or extradural soft tissue tumour, which has important management implications. 4 • Provides information about the site, nature and extent of neurological involvement and the paravertebral spread of tumour. 1, 5-7 • Detects the presence of bone marrow involvement. 8 • Detects compression at multiple levels. 1, 2, 9 • Differentiates malignant from benign collapsed vertebral bodies. 6 • Improved sensitivity for detection of intramedullary metastases, leptomeningeal involvement, and paraspinal metastases with intravenous contrast medium. 4, 10 • More cost-effective than CT myelogram. 11

44 + COMPUTED TOMOGRAPHY • Alternative if MRI is unavailable. 3 • Limitations: 3 • Invasive test with risk of complications (eg. acute neurological decompensation in patients with high grade blocks). • Lack of visualisation of the entire spine. • Use of intravenous contrast material. • Exposure to ionising radiation.

45 REFERENCES 1. Husband DJ, Grant KA, Romaniuk CS. MRI in the diagnosis and treatment of suspected malignant spinal cord compression. Br J Radiology 2001; 74: 15-23. (Prospective study 280 consecutive patients – Level II evidence) 2. Cook AM, Lau TN, Tomlinson MJ, et al. Magnetic resonance imaging of the whole spine in suspected malignant spinal cord compression: impact on management. Clin Oncol 1998; 10: 39-43. (Cohort of 127 patients – Level III evidence) 3. Carmody RF, Yang PJ, Seelly GW, et al. Spinal cord compression due to metastatic disease: diagnosis with MR imaging vs myelography. Radiology 1989: 173: 225- 229. (Prospective study 70 patients – Level III evidence) 4. Loughrey GJ, Collins CD, Todd SM, et al. Magnetic resonance imaging in the management of suspected spinal canal disease in patients with known malignancy. Clinical Radiology 2000; 55: 849-855. (Cohort of 150 patients – Level III evidence) 5. Williams MP, Cherryman GR, Husband JE. Magnetic resonance imaging in suspected metastatic spinal cord compression. Clinical Radiology 1989; 40: 286- 290. (Cohort of 55 patients – Level III evidence) 6. Li KC, Poon PY. Sensitivity and specificity of MRI in detecting malignant spinal cord compression and in distinguishing malignant from benign compression fractures of the vertebrae. Magnetic Resonance Imaging 1988; 6: 547-556. (Retrospective study cohort of 75 patients – Level III evidence) 7. Smoker WR, Godersky JC, Knutzon RK, et al. The role of MR imaging in evaluating metastatic spinal disease. AJR 1987; 149: 1241-1248. (Retrospective study cohort of 58 patients – Level III evidence) 8. Daffner RH, Lupetin AR, Dash N, et al. MRI in the detection of malignant infiltration of bone marrow. AJR 1986; 146: 353-358. (Prospective study 80 patients – Level II/III evidence) 9. Heldman U, Myschetzky PS, Thomsen HS. Frequency of unexpected multifocal metastasis with acute spinal cord compression: evaluation by low-field MR imaging in cancer patients. Acta Radiologica 1997; 38: 372-375. (Retrospective study cohort of 240 patients – Level II/III evidence) 10. Sze G. Gadolinium-DTPA in spinal disease. Radio Clin N America 1998; 26: 1009- 1024. (Review) 11. Jordon JE, Donaldson SS, Enzmann DR. Cost effectiveness and outcome assessement of magnetic resonance imaging in diagnosing cord compression. Cancer 1995; 75: 2579-2586. (Retrospective analysis – Level III evidence)

Further Reading 1. Johnstone RA. The management of acute spinal cord compression. J Neurol Neurosurg Psychiatry 1993; 56: 1046-1054.

46 DEMENTIA

CLINICAL ASSESSEMENT AND NEUROIMAGING IN DEMENTIA • The neurological history and examination are essential components of the diagnostic work up of dementia and may reveal important clues to the aetiology of the patient’s dementia. 1 • Alzheimer’s disease (AD) is the most common type of dementia and NINCDS- ADRDA criteria for probable AD includes: 2 1. The insidious onset and progressive worsening of dementia. 2. Prominent difficulty with memory (especially retention and retrieval of new information). 3. Onset after age 60. 4. No focal signs or gait difficulties on neurological examination, especially early in the course. 5. Exclusion of other causes of dementia (systemic or intracranial disorders). • Neuroimaging (CT or MRI) is indicated to exclude other (treatable) intracranial disorders that might cause dementia, such as stroke, intra-axial or extra-axial tumours, subdural haematomas, hydrocephalus, and Creutzfeldt-Jakob disease. 1, 2

COMPUTED TOMOGRAPHY (CT) • Useful for excluding causes of dementia other than Alzheimer’s disease. 3, 4 • May show atrophy, white matter changes, space-occupying lesions, and vascular disease. 3-5 • Permits detection of hippocampal atrophy, which may be specific for Alzheimer’s disease and may be useful for early detection and differential diagnosis. 5-7 • Limitations: 4 • Inability to distinguish grey and white matter. • May miss old haemorrhage or haemorrhage from severe anaemia. • Poor visualisation of the posterior fossa. • May miss infarctions. 47

MAG N ETIC RESONANCE IMAGING (MRI) • Higher sensitivity than CT in detecting most intracranial pathologies. 8 • MR-based volumetric measurements of the hippocampal formation allow differentiation of patients with probable AD from normal elderly individuals. 9-10 • Patients with normal pressure hydrocephalus with classic clinical triad (dementia, gait disturbance, and urinary incontinence) and CT/MRI findings of enlarged ventricles and absence of or only mild cortical atrophy, are more likely to respond to shunt and may benefit from further imaging with SPECT cisternography. 11 • Increased CSF flow void through cerebral aqueduct on MRI appears to correlate with a good response to shunt surgery. 12 • Advantages: 4 • Allows differentiation of grey and white matter. • Ability to image small lacunar and posterior fossa lesions. • Superior to CT in imaging subacute haemorrhage. • Permits direct visualisation of hippocampal formation. • Disadvantages: • Contraindicated in patients with metallic implants. • Relative contraindications (claustrophobic, anxious patients). • Limited availability and high expense.

SING L E PHOTON EMISSION COMPUTED TOMOGRAPHY (SPECT) • Physiological imaging technique that is most useful in providing information on neuronal function (eg cerebral blood flow). 8 • May assist in the evaluation of the differential diagnosis of dementing illness. 13, 14, 16 • Assists in confirming the diagnosis of Alzheimer’s disease (reveals bilateral temporo-parietal, posterior cingulate gyrus and/or hippocampal hypoperfusion and hemispheric asymmetry in Alzheimer’s disease – consistent functional patterns in Alzheimer’s disease). 5, 15-17 • Routine use of SPECT for diagnosis of Alzheimer’s disease is not currently recommended, as a normal SPECT does not exclude the diagnosis of Alzheimer’s disease. 15-17 • Advantages: • Gives functional information. • More widely available compared to PET scan. • Limitations: lower spatial resolution than PET (does not identify deep structures as well).

SPECT NUCLEAR MEDICINE CISTERNOGRAPHY • Useful in the evaluation of patients with normal pressure hydrocephalus as it allows distinction of patients who are likely to respond to shunt from non-responders. 18

48 POSITRON EMISSION TOMOGRAPHY (PET) • Provides information on: 4 1. Neuronal function 2. Glucose metabolism 3. Cerebral blood flow 4. Receptor characteristics (eg density, affinity). • Assists in confirming the diagnosis of Alzheimer’s disease (Shows characteristic reductions in glucose metabolic rates and cerebral blood flow in patients with probable and definitive AD in the parietal, temporal, and posterior cingulate regions). 14, 19-21 • Can differentiate patients with Alzheimer’s disease from patients with other dementias (such as Multi infarct dementia, Huntington’s disease and Pick’s disease) and from cognitively intact people. 19-21 • ~90% sensitivity and 70% specificity in the diagnosis of Alzheimer’s disease. 20, 21

49 REFERENCES 1. Report of the Quality Standards Subcommittee of the American Academy of Neurology. Practice parameter for diagnosis and evaluation of dementia. (Summary statement) Neurology 1994; 44(11): 2203-2206. 2. Mckhann G, Drachman D, Folstein M, et al. Clinical diagnosis of Alzheimer’s disease: Report of the NINCDS-ARDA Work Group under the auspices of Department of Health and Human Services Task Force on Alzheimer’s disease. Neurology 1984; 34(7): 939-944. 3. Scheltens P. Early diagnosis of dementia: neuroimaging. J Neurol 1999; 246: 16-20. (Review) 4. Small GW, Leitter F. Neuroimaging for diagnosis of dementia. J Clin Psychiatry 1998; 59(S11): 4-7. (Review) 5. Jobst KA, Hindley NJ, King E, et al. The diagnosis of Alzheimer’s disease: a question of image? J Clin Psychiatry 1994; 55(11, suppl): 22-31. (Cohort of 71 histologically confirmed cases and 84 living controls - Level II/III evidence) 6. Jobst KA, Smith AD, Szatmari M, et al. Detection in life of confirmed Alzheimer’s disease using a simple measurement of medial temporal lobe atrophy by computed tomography. Lancet 1993; 340: 1179-1183. (Retrospective study 44 case controls – Level IV evidence) 7. De Leon MJ, George AE, Stylopoulos LA, et al. Early marker for Alzheimer’s disease: the atrophic . Lancet 1989; September 16: 672-673. (Cohort of 175 patients + controls – Level II evidence) 8. Jagust WJ, Eberling JL. MRI, CT, SPECT, PET: their use in diagnosing dementia. Geriatrics 1991; 46(2): 28-35. 9. Jack CR Jr, Petersen RC, O’Brien PC, et al. MR based hippocampal volumetry in the diagnosis of Alzheimer’s disease. Neurology 1992; 42: 183-188. (Cohort of 20 patients + 22 controls – Level III evidence) 10. Pantel J, Schroder J, Schad LR, et al. Quantitative magnetic resonance imaging and neuropsychological functions in dementia of the Alzheimer’s type. Pscychol Med 1997; 27: 221-229. (Cohort of 20 patients with Alzheimer’s dementia and 10 health controls – Level III evidence) 11. Vanneste J, Augustijn P, Tan WF, et al. Shunting normal pressure hydrocephalus: the predictive value of combined clinical and CT data. Journal of Neurology, Neurosurgery, and Psychiatry 1993; 56: 251-256. (Retrospective study cohort of 166 consecutive patietnts shunted for presumed NPH – Level III evidence) 12. Bradley WG Jr, Whittemore AR, Kortman KE, et al. Marked cerebrospinal fluid void: indicator of sucessful shunt in patients with suspected normal-pressure hydrocephalus. Radiology 1991; 178: 459-466. (Retrospective study cohort of 20 patients – Level III evidence) 13. Osimani A, Ichise M, Chung D-G, et al. SPECT for differential diagnosis of dementia and correlation of rCBF with cognitive impairment. Can J Neurol Sci 1994; 21: 104-111. (Cohort of 30 patients – Level III evidence) 14. Mielke R, Pietrzyk U, Jacobs A, et al. HMPAO SPET and FDG PET in Alzheimer’s disease and vascular dementia: comparison of perfusion and metabolic pattern. Eur J Nucl Med 1994; 21: 1052-1060. (Cohort of 20 patients with probable AD and 12 patients with vascular dementia – Level III evidence) 15. Van Gool WA, Walstra GJ, Terunisse S, et al. Diagnosing Alzheimer’s disease in elderly, mildly demented patients: the impact of routine single photon emission computed tomography. J Neurol 1995; 242(6): 401-405. (Prospective study 110 consecutive patients – Level II evidence)

50 16. Read SL, Miller BL, Mena I, et al. SPECT in dementia: clinical and pathological correlation. J Am Geriatr Soc 1995; 43: 1243-1247. (Cohort of 27 patients – Level III evidence) 17. Hanyu H, Abe S, Arai H, et al. Diagnostic accuracy of single photon emission computed tomography in Alzheimer’s disease. Gerontology 1993; 39(5): 260-266. (Retrospective study 219 patients – Level III/IV evidence) 18. Larsson A, Arlig A, Bergh A-C, et al. Quantitative SPECT cisternography in normal pressure hydrocephalus. Acta Neurol Scand 1994; 90: 190-196. (Prospective study 39 consecutive patients – Level II evidence) 19. Silverman DHS, Cummings JL, Small GW, et al. Added clinical benefit of incorporating 2-Deoxy-2-18F-Fluoro-D-Glucose with positron emission tomography into the clinical evaluation of patients with cognitive impairment. and Biology 2002; 4: 283-293. (Decision tree analysis – Level II evidence) 20. Silverman DHS, Small GW, Chang CY, et al. Positron emission tomography in evaluation of dementia: regional brain metabolism and long-term outcome. JAMA 2001; 286: 2120-2127. (Multicenter study 284 patients with symptoms of dementia – Level II evidence) 21. Hoffman JM, Welsch-Bohmer KA, Hanson M, et al. FDG PET imaging in patients with pathologically verified dementia. J Nucl Med 2000; 41: 1920-1928. (Cohort of 22 patients – Level III evidence)

Further Reading 1. Savoiardo M, Griscoli M. Imaging dementias. Eur Radiol 2001; 11: 484-492. 2. McMahon PM, Araki SS, Neumann PJ, et al. Cost-effectiveness of functional imaging tests in the diagnosis of Alzheimer disease. Radiology 2000; 217: 58-68. 3. Silverman DHS. Neuroimaging in the evaluation of dementia: the diagnostic value of FDG-PET and other imaging modalities. Diagn Imag 2001; 23: 122-128.

51 HEAD TRAUMA

SKULL RADIOGRAPHS • Not routinely indicated. If imaging is clinically indicated, CT is the investigation of choice. • Useful for imaging of calvarial fractures, penetrating injury, and radiopaque foreign bodies. 1 • Assuming that there is no difficulty in assessing the patient clinically, radiographs are not indicated if there is: 1 • No significant scalp injury. • No history of significant loss of consciousness or amnesia. • No neurological symptoms or signs. • No cerebrospinal fluid leak.

CRANIAL COMPUTED TOMOGRAPHY • Cranial CT is indicated in the following head-injured patients: 2-4 1. Patients who are drug and alcohol-free and are: • not fully conscious and orientated and/or have • abnormal neurological signs or symptoms or • abnormal skull x-rays 2. Patients under the influence of mind-altering substances including alcohol • with abnormal neurological symptoms, signs or skull x-rays 3. Patients under the influence of mind-altering substances including alcohol who do not have abnormal neurological symptoms, signs or skull x-rays on initial assessment who on observation: • show deterioration in the Glascow Coma Score (GCS) • show no change in GCS at 4 hours post-trauma 4. All patients with GCS <15 at 6 hours post-trauma should be CT scanned. 5. All head-injured patients on anti-coagulants and long-term aspirin. • Not routinely performed in patients with history of a brief loss of consciousness who are fully orientated in time, place and person with no abnormal neurological symptoms or signs and who have good quality normal skull radiographs. 4 • However, some centers use cranial CT in patients with blunt head trauma associated with history of loss of consciousness or amnesia but normal neurological examination, to allow patients with negative CT scans to be discharged home from emergency department. 5 • Routine CT of the craniocervical junction, in addition to CT of the head, is useful in patients with substantial cranial trauma. 6

52 REFERENCES 1. Masters SJ, McClean PM, Arcarese JS, et al. Skull X-ray examinations after head trauma. Recommendations by a multidisciplinary panel and validation study. NEJM 1987; 316(2): 84-91. (Prospective study 7035 patients – Level II evidence) 2. Miller EC, Holmes JF, Derlet RW. Utilizing clinical factors to reduce head CT scan ordering for minor head trauma patients. J Emerg Med 1997; 15: 453-457. (Prospective study 2143 patients – Level II evidence) 3. Schynoll W, Overton D, Krome R, et al. A prospective study to identify high-yield criteria associated with acute intracranial computed tomography findings in head- injured patients. Am J Emerg Med 1993; 11: 321-326. (Multicenter prospective study 264 patients – Level II evidence) 4. Udstuen GJ, Clear JM. Imaging of acute in the adult. Seminars in US, CT, and MRI 2001; 22(2): 135-147. 5. Nagy KK, Joseph KT, Krosner SM, et al. The utility of computed head tomography after minimal head injury. J Trauma 1999; 46: 268-270. (Prospective study 1170 patients – Level II evidence) 6. Link TM, Schuierer G, Hufendiek A, et al. Substantial head trauma: value of routine CT examination of the cervicocranium. Radiology 1995; 196: 741-745. (Prospective study 202 consecutive patients with GCS scores of 3-6 – Level II evidence)

53

INVESTIGATION OF SEIZURE/FIT

MAGNETIC RESONANCE IMAGING (MRI) • Imaging modality of choice for the evaluation of first seizure and refractory epilepsy. 1, 2 • Usually recommended in all patients with first seizure. 3, 4 • Imaging technique used depends on the specific type of seizures suspected on clinical assessment eg temporal lobe protocol for clinically suspected temporal lobe epilepsy and fine slice through region of interest in clinically suspected extratemporal epilepsy. 2 • The identification of a lesion in extratemporal areas or of atrophy or increase signal in temporal lobe by qualitative or quantitative MRI, has a high correlation with the site of epileptogenesis. 5 • Allows diagnosis and provides prognostic information which can alter management for the individual patient with newly diagnosed partial seizures. 6 • Superior to CT in detection of cerebral lesions related to epilepsy, especially gliomas and cavernous malformations. Therefore, MRI may be needed to image patients with normal or inconclusive CT. 3, 7-10 • Limitations: expensive and limited availability.

54 COMPUTED TOMOGRAPHY (CT) • When MRI is unavailable, CT is the next best imaging modality for establishing the cause of seizures and in disclosing early lesions. 11, 12 • Can identify large structural abnormalities and remains adequate in the emergency or perioperative setting. 1, 13, 14 • CT head with contrast enhancement is particularly useful in the setting of a focal seizure, neurological deficit, possible trauma, or absence of history of alcohol misuse. • Limitations: less sensitive than MRI at characterising the nature of the abnormality and demonstrating more subtle lesions such as encephalitis, hyperacute infarction, small mass lesions including tumours and vascular malformations, hippocampal sclerosis and developmental cortical malformations. 7-10

MAGNETIC RESONANCE IMAGING IN REFRACTORY EPILEPSY • Essential for presurgical evaluation of patients with uncontrolled epilepsy considered for surgery. 15, 16 • Quantitative assessment of hippocampal volume is useful in cases where qualitative assessment is equivocal, the hippocampi appear symmetric/normal or when there is questionable bilateral hippocampal atrophy. 1, 5 • Provides the anatomical resolution necessary for proper interpretation of functional imaging studies such as, SPECT and FDG-PET.

SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY (SPECT) • Functional imaging technique useful in localisation of the seizure focus in the presurgical evaluation of patients with medically refractory epilepsy. 5, 17 • Useful in cases where there is discordant data in temporal lobe epilepsy, non- lesional temporal or extratemporal epilepsy. • A seizure focus typically manifests as a focus of hypoperfusion on interictal examinations and as a focus of increased perfusion on ictal examinations. 17 • Ictal scans are compared with interictal baseline examination to detect subtle changes.17 • Usually concurrent video EEG is required to allow correlation of the blood flow changes with clinical and electrophysiological changes. • Limitations: difficult interpretation requiring knowledge of seizure type, clinical activity, time of ictal injection in relation to seizure onset, and MRI findings. 5

POSITRON EMISSION TOMOGRAPHY (PET) • Functional imaging technique allows presurgical localisation of seizure focus in patients with medically refractory partial seizures. 5, 18 • During focal seizures, cerebral metabolic activity increases in the epileptogenic area, and PET reveals localised hypermetabolism. Interictal FDG-PET is useful for localisation of the epileptogenic region in patients with clinical syndrome of refractory mesial temporal lobe epilepsy or with suspected neocortical temporal lobe epilepsy. 18 • Interictal FDG-PET has sensitivity of 84% and specificity of 86% for temporal lobe epilepsy and 33% sensitivity and 95% specificity for extratemporal epilepsy.5 • Useful in cases where there is discordant information eg EEG shows right temporal focus and MRI shows left mesial temporal sclerosis, or if MRI is normal in a patient with clinical/ electrographic evidence of temporal lobe epilepsy or if there is bilateral mesial temporal sclerosis. Also may be of value where there is “dual

55 pathology” eg temporal sclerosis and a structural abnormality of uncertain significance elsewhere. • Limitations: expensive and limited availability.

56 REFERENCES 1. Connor SEJ, Jarosz JM. Magnetic resonance imaging of patients with epilepsy. Clinical Radiology 2001; 56: 787-801. (Review) 2. Bradley WG, Shey RB. MR Imaging evaluation of seizures. Radiology 2000; 214: 651-656. 3. King MA, Newton MR, Jackson GD, et al. Epileptology of the first-seizure presentation: a clinical, electroencephalographic, and magnetic resonance imaging study of 300 consecutive patients. Lancet 1998; 352: 1007-1011. (Prospective study 300 consecutive patients – Level II evidence) 4. Scheuer ML, Pedley TA. The evaluation and treatment of seizures. NEJM 1990; 323(21):1468-1474. 5. Spencer SS. The relative contributions of MRI, SPECT, and PET imaging in epilepsy. Epilepsia 1994; 35(S6): S72-S89. (Retrospective study – Level III evidence) 6. Van Paesschen W, Duncan JS, Stevens JM, et al. Etiology and early prognosis of newly diagnosed partial seizures in adults: a quantitative hippocampal MRI study. Neurology 1997; 49: 753-757. (Prospective study 63 patients – Level III evidence) 7. Latack JT, Abou-Khalil BW, Siegel GJ, et al. Patients with partial seizures: evaluation by MR, CT and PET imaging. Radiology 1986; 159: 159-163. (Cohort of 50 patients – Level III evidence) 8. Laster DW, Penry JK, Moody DM, et al. Chronic seizure disorders: contribution of MR imaging when CT is normal. Am J Neuroradiol 1985; 6: 177-180. (Prospective study 34 patients with normal neurological examination and CT – Level II/III evidence) 9. Bergen D, Bleck T, Ramsey R, et al. Magnetic resonance imaging as a sensitive and specific predictor of neoplasms removed for intractable epilepsy. Epilepsia 1989; 30: 318-321. (Cohort of 23 patients – Level III evidence) 10. Rigamonti D, Hadley MN, Drayer BP, et al. Cerebral cavernous malformations: incidence and familial occurrence. NEJM 1988; 319: 343-347. (Cohort of 64 first and second degree relatives of 24 patients with cerebral cavernous malformations – Level III evidence) 11. Ramirez-Lassepas M, Cipolle RJ, Morillo LR, et al. Value of computed tomographic scan in the evaluation of adult patients after their first seizure. Ann Neurol 1984; 15: 536-543. (Retrospective study cohort of 184 patients – Level III evidence) 12. Theodore WH, Dorwart R, Holmes M, et al. Neuroimaging in refractory partial seizures: comparison of PET, CT and MRI. Neurology 1986; 36: 750-759. (Cohort of 36 patients – Level III evidence) 13. Sempere AP, Villaverde FJ, Martinez-Menendez B, et al. First seizure in adults: a prospective study from the emergency department. Acta Neurol Scand 1992; 86: 134-138. (Prospective study 98 consecutive patients – Level III evidence) 14. Schoenenberger RA, Heim SM. Indication for computed tomography of the brain in patients with first uncomplicated generalized seizure. BMJ 1994; 309: 986-989. (Prospective observational study 119 patients – Level III evidence) 15. Commision on Neuroimaging of the International League Against Epilepsy. Guidelines for neuroimaging evaluation of patients with uncontrolled epilepsy considered for surgery. Epilepsia 1998; 39(2): 1375-1376. 16. Sperling MR, Wilson G, Engel J Jr, et al. Magnetic resonance imaging in intractable partial epilepsy: correlative studies. Ann Neurol 1986; 20: 57-62. (Prospective study 35 patients – Level II/III evidence) 17. Mullan BP, O’Connor MK, Hung JC. Single photon emission computed tomography. Neuroimaging Clin N Am 1995; 5(4): 647-673.

57 18. DeCarli C, McIntosh AR, Blaxton TA. Use of positron emission tomography for the evaluation of epilepsy. Neuroimaging Clinics N America 1995; 5(4): 623-645.

58 INVESTIGATION OF ORBITAL PATHOLOGY

PLAIN RADIOGRAPHY • Plays a limited role in the detailed evaluation and management of orbital disease and trauma. 1-3 • May be useful in screening for intraocular foreign bodies and in detection of orbital fractures directly or through indirect findings (such as asymmetrical opacification by haemorrhage of a paranasal sinus adjacent to a particular orbital surface, and orbital emphysema). 2, 4 • Limitations: • 50% rate of false negatives and nondiagnostic in 30% in the evaluation of orbital blowout fractures. 3 • Poor visualisation of medial orbital wall and orbital floor fractures.

COMPUTED TOMOGRAPHY • Imaging modality of choice for the investigation of orbital trauma, some inflammatory diseases, Grave’s ophthalmopathy, and suspected retinoblastoma. 5, 6 • Gives the best illustration of fine bony structures of the midface and orbits. 5, 6 • Allows detection of the orbital fractures and assessment of the extent of injury in the evaluation of patients with orbital trauma. 3 • High sensitivity and specificity for the detection and localisation of intraocular and orbital metal, glass and stone foreign body. 8, 9 • Limitations: • Less accurate for detection of wooden foreign bodies. 7

MAGNETIC RESONANCE IMAGING • Imaging modality of choice for the evaluation of: 6 • Ocular lesions, the optic nerve apparatus, cranial nerve palsies, and retrobulbar disease with potential intracranial extension. 10-12 • Intraocular tumours such as uveal melanoma (because of superior delineation of the extent of the disease and unique paramagnetic signal characteristics of melanin). 13, 14

59 • Compared to CT, MRI allows more accurate depiction of extension of optic nerve or sheath tumours into the optic chiasm, optic tracts and lateral geniculate bodies of thalami. 10, 15 • As a predictor of multiple sclerosis, it can help to prognosticate the development of MS after optic neuritis. 16 • Once plain films or CT of the orbit has screened metallic fragments, MRI is valuable in the examination of the optic nerve and globe for injury and hence useful adjunct in the assessment of orbital injury. 5 • Advantages: 5 • Superior soft tissue resolution. • Distinguishes the layers of the globe partially (sclera is separated from the uvea and retina). • Allows visualisation of anterior chamber structures not seen on CT. • Limitations: 5 • Possibility of a metal foreign body within the orbit is an absolute contraindication because of potential for movement of a ferromagnetic foreign body within the fluctuating magnetic fields of a MR machine could result in blindness. • Poor visualisation of the bone.

60 REFERENCES 1. Mosley IF. The plain radiograph in ophthalmology: a wasteful and potentially dangerous anachronism. J Royal Soc Med 1991; 84: 76-80. (Prospective study 822 consecutive plain films – Level II evidence) 2. Bhattacharya J, Mosley IF, Fells P. The role of plain radiography in the management of suspected orbital blow-out fractures. Br J Radiology 1997; 70: 29-33. (Retrospective study 100 consecutive patients – Level III evidence) 3. Brady SM, McMann MA, Mazzoli RA, et al. The diagnosis and management of orbital blowout fractures: update 2001. Am J Emerg Med 2001; 19: 147-154. (Retrospective study 59 orbital blow out fractures – Level IV evidence) 4. Otto PM, Otto RA, Virapongse C, et al. Screening test for detection of metallic foreign objects in the orbit before magnetic resonance imaging. Invest Radiology 1992; 27: 308-311. (Prospective study 20 metal particles in 5 human cadaver orbits – Level III evidence) 5. Go JL, Vu VN, Lee KJ, et al. Orbital trauma. Neuroimaging Clinics of North America 2002; 12(2): 311-324. 6. Belden CJ, Zinreich SJ. Orbital imaging techniques. Seminars in US, CT and MRI 1997; 18(6): 413-422. (Review) 7. Maya MM, Heier LA. Orbital CT: current use in the MR era. Neuroimaging Clinics of North America 1998; 8(3): 651-693. 8. Lakits A, Prokesch R, Scholda C, et al. Orbital helical computed tomography in the diagnosis and management of eye trauma. Ophthalmology 1999; 106: 2330-2335. (Prospective study 36 consecutive patients – Level II/III evidence) 9. Gor DV, Kirsch CF, Leen J, et al. Radiologic differentiation of intraocular glass: evaluation of imaging techniques, glass types, size, and effect of intraocular haemorrhage. AJR 2001; 177: 1199-203. (Prospective study 42 porcine eyes implanted with glass – Level II/III evidence) 10. Ettl A, Kramer J, Daxer A, et al. High resolution magnetic resonance imaging of neurovascular orbital anatomy. Ophthalmology 1997; 104: 869-877. (Level III evidence) 11. Tonami H, Tamamura H, Kimizu K, et al. Intraocular lesions in patients with systemic disease: findings on MR imaging. AJR 1990; 154(2): 385-389. (Prospective study 15 patients – Level III evidence) 12. Breslau J, Dalley RW, Tsuruda JS, et al. Phased-array surface coil MR of the orbits and optic nerves. AJNR 1995; 16: 1247-1251. (Cohort of 24 cases – Level III evidence) 13. Peyster RG, Augsburger JJ, Shields JA, et al. Intraocular tumors: evaluation with MR imaging. Radiology 1988; 168(3): 773-779. (Retrospective study 67 case controls – Level IV evidence) 14. Gomori JM, Grossman RI, Shields JA, et al. Choroidal melanomas: correlation of NMR spectroscopy and MR imaging. Radiology 1986; 158: 443-445. (Prospective study 6 enucleated eyes – Level III evidence) 15. Gass A, Barker GJ, MacManus D, et al. High resolution magnetic resonance imaging of the anterior visual pathway in patients with optic neuropathies using fast spin echo and phased array local coils. J Neurol Neurosurg Psychiatry 1995; 58: 562-569. (Cohort of 15 normal controls and 57 patients – Level III evidence) 16. Dunker S, Wiegand W. Prognostic value of magnetic resonance imaging in monosymptomatic optic neuritis. Ophthalmology 1996; 103: 1768-1773. (Cohort of 22 patients – Level III evidence) Further Reading 1. Duvoisin B, Zanella FE, Sievers KW. Imaging of the normal and pathological orbit. Eur Radiol 1998; 8: 175-188.

61 INVESTIGATION OF SUSPECTED PITUITARY FOSSA LESION

PITUITARY FOSSA LESION • Pituitary adenomas are the most common lesions of the . They may secrete prolactin, TSH, GH, ACTH or gonadotropins. 1-3 • Plain radiography is insensitive and nonspecific for evaluation of sellar pathology. 1- 3 • Pituitary microadenoma and even small pituitary macroadenomas are frequently associated with a normal sella size. 1-3

MAGNETIC RESONACE IMAGING • Gadolinium enhanced MRI is the imaging modality of choice for investigation of suspected pituitary fossa lesion. 1-4 • Superior diagnostic accuracy compared to CT. 4-9 • Advantages: • Accurate depiction of the anatomy of the pituitary gland, infundibulum, optic chiasm, cavernous sinuses, and neighbouring vascular structures. 4, 5, 7, 10 • Helps differentiate fat, haemorrhage and cystic areas from tumour tissue. 11 • Disadvantages: expensive and limited availability.

COMPUTED TOMOGRAPHY • Useful when MRI is unavailable. 1-3 • Superior to MRI in demonstration of bony erosion. 5, 8 • Inferior to MRI for distinguishing the tumour from the optic chiasm, and in diagnosis of cavernous sinus invasion. 4, 8, 12 • Advantages: relatively less expensive and widely available. • Disadvantages: exposure to ionising radiation.

62 REFERENCES 1. Fitzpatrick M, Tartaglino LM, Hollander MD, et al. Imaging of sellar and parasellar pathology. Radiologic Clinics of North America 1999; 37(1): 101-121. 2. Naidich MJ, Russell EJ. Current approaches to imaging of the sellar region and pituitary. Endocrinology and Metabolism Clinics of North America 1999; 28(1): 45- 79. 3. Swallow CE, Osborn AG. Imaging of sella and parasellar disease. Sem Ultrasound, CT, and MRI 1998; 19(3): 257-271. 4. Johnson MR, Hoare RD, Cox T, et al. The evaluation of patients with a suspected pituitary microadenoma: computer tomography compared to magnetic resonance imaging. Clinical Endocrinology 1992; 36: 335-338. (Prospective study 19 patients – Level II evidence) 5. Davis PC, Hoffman JC Jr, Spencer T, et al. MR imaging of pituitary adenoma: CT, clinical, and surgical correlation. AJR 1987; 148: 797-802. (Prospective study 25 patients – Level III evidence) 6. Nichols DA, Laws ER, Houser OW, et al. Comparison of magnetic resonance imaging and computed tomography in the preoperative evaluation of pituitary adenomas. Neurosurgery 1988; 22: 380-385. (Retrospective study 20 surgically verified pituitary adenoma – Level IV evidence) 7. Guy Rl, Benn JJ, Ayers AB, et al. A comparison of CT and MRI in the assessment of the pituitary and parasellar regions. Clinical Radiology 1991; 43: 156-161. (Prospective study 40 patients – Level II/III evidence) 8. Lundin P, Bergstrom K, Thomas KA, et al. Comparison of MR imaging and CT in pituitary macroadenomas. Acta Radiol 1991; 32: 189-196. (Retrospective study 65 case controls – Level IV evidence) 9. Kulkarni MV, Lee KF, McArdle CB, et al. 1.5-T MR imaging of pituitary microadenomas: technical considerations and CT correlation. AJNR 1988; 9: 5-11. (Prospective study 37 patients – Level III evidence) 10. Cottier JP, Destrieux C, Brunereau L, et al. Cavernous sinus invasion by pituitary adenoma: MR imaging. Radiology 2000; 215: 463-469. (Retrospective study 106 patients – Level III evidence) 11. Kucharczyk W, Davis DO, Kelly WM, et al. Pituitary adenomas: high-resolution MR imaging at 1.5 T. Radiology 1986; 161: 761-765. (Cohort of 38 patients – Level III/IV evidence) 12. Stein AL, Levenick MN, Kletzky OA. Computed tomography versus magnetic resonance imaging for the evaluation of suspected pituitary adenomas. Obstet Gynaecol 1989; 73: 996-999. (Cohort of 22 patients – Level II/III evidence)

Further Reading 1. Evanson EJ. Imaging the pituitary gland. Imaging 2002; 14: 93-102.

63 STROKE

IMAGING IN STROKE • Stroke is a clinical syndrome. In the investigation of stroke, imaging is used to differentiate: 1 1. Vascular from non-vascular lesions, such as tumours or infections. 2. Ischaemic from haemorrhagic stroke. 3. Arterial from venous infarction. 4. Anterior and posterior circulation ischaemic strokes to determine whether a tight carotid stenosis is symptomatic or not.

CRANIAL COMPUTED TOMOGRAPHY (CT) • Initial imaging modality of choice in patients with acute stroke. 1-5 • Useful in screening patients for potential thrombolytic therapy. 6, 7 • Highly sensitive in distinguishing haemorrhagic from non-haemorrhagic stroke. 2 • Nearly 100% accuracy for detection of intra-parenchymal haemorrhage (except for very anaemic patients with isoattenuating haematomas) if performed within 5-7 days of stroke – thereafter small haemorrhages are indistinguishable form infarcts. 2 • Sensitivity of early CT in detecting acute strokes depends on the duration, location, and size of the infarct (50-60% sensitivity within first 24 hours). 8-10 • A follow-up CT of the head is useful when the initial CT scan result is negative and documentation of the presence, location and extension of the ischaemic infarction is needed, or to identify haemorrhagic transformation, hydrocephalus, oedema, new stroke etc if the patient deteriorates. 1 • Advantages: relatively inexpensive and widely available compared to MRI. • Limitations: relative lack of sensitivity for the detection of early ischaemia. 8

MAGNETIC RESONANCE IMAGING (MRI) • Not recommended for routine evaluation of patients with acute stroke. 2

64 • Superior to CT in: 2 • The early documentation of infarction (90% sensitivity for detection of cerebral ischaemic infarction within the first 24 hours of stroke onset). 8 • Identification of a haemorrhagic component and the presence of associated features, including mass effect. • In detection of lacunar and small cortical strokes, and stroke in the posterior fossa where CT is limited due to beam-hardened artefact from the adjacent skull base. • Useful in: 1 • Distinguishing haemorrhage from infarct in patients presenting late after stroke. • “Difficult” strokes such as suspected venous infarction or carotid or vertebral dissections. • Demonstration of posterior circulation strokes. • Identification of small haemorrhage. • When dating of the haemorrhage is indicated. • Diffusion weighted imaging is superior to conventional MRI and CT in the examination of patients with acute stroke within 24 hours of presentation. 10-14 • Advantages: • Ability to evaluate large vessel patency and perfusion characteristics. • Ability to distinguish acute from chronic ischaemia. • Limitations: • Decreased resolution of early intracranial haemorrhage when compared with CT. • Contraindicated in patients with cardiac pacemakers, surgical clips, cochlear implants etc. • Expensive and limited availability.

CAROTID DOPPLER ULTRASOUND • Screening modality of choice for the evaluation of carotid vessels in carotid distribution ischaemic stroke in a patient suitable for surgery. 15, 16 • Advantages: relatively inexpensive and widely available.

ECHOCARDIOGRAPHY • Useful in the detection of cardiac sources of cerebral emboli, thereby allowing the provision of appropriate therapy and preventing recurrent stroke. 17 • Detects intracardiac masses (thrombus, vegetation or tumour) in about 4% (with transthoracic echocardiography) to 11% (with transoesophageal echocardiography) of ischaemic stroke patients. 17 • Lower yield among patients without clinical evidence of cardiac disease by history, physical examination, electrocardiography or chest radiography (<2%) than among patients with clinical evidence of cardiac disease (<19%). 17 • Patients with ischaemic stroke and documented intracardiac thrombus are at increased risk for embolic events and this risk can be reduced with anticoagulant therapy. 17

MAGNETIC RESONANCE ANGIOGRAPHY (MRA) • Useful in the evaluation of cranial vessels. 18, 19

CONVENTIONAL ANGIOGRAPHY • “Gold standard” for imaging of lumen of arterial vessels. 19 • Disadvantages: expensive, invasive and potential risk and complications (vascular damage, ionising radiation, stroke, and systemic reactions to contrast agents) 65 REFERENCES 1. Wardlaw JM. Radiology of stroke. J Neurol Neurosurg Psychiatry 2001; 70(S1): i7- i11. (Review) 2. Culebras A, Kase CS, Masdeu JC, et al. Practice guidelines for the use of imaging in transient ischemic attacks and acute stroke: a report of the Stroke Council, American Heart Association. Stroke 1997; 28: 1480-1497. 3. Beauchamp NJ Jr, Barker PB, Wang PY, et al. Imaging of acute cerebral ischemia. Radiology 1999; 212: 307-324. (Review) 4. Gaskill-Shipley MF. Routine CT evaluation of acute stroke. Neuroimaging Clinics of North America 1999; 9(3): 411-422. (Review) 5. Moonis M, Fisher M. Imaging of acute stroke. Cerebrovasc Dis 2001; 11: 143-150. (Review) 6. Hacke W, Kaste M, Fieschi C, et al. Intravenous thrombolysis with recombinant tissue plasminogen activator for acute hemisphere stroke: the European Cooperative Acute Stroke Study. JAMA 1995; 274: 1017-1025. (Level I evidence) 7. National institute of neurological disorders and stroke r-tPA Study Group. Tissue plasminogen activator for acute ischaemic stroke. NEJM 1995; 355: 1581-1587. (Level I evidence) 8. Bryan RN, Levy LM, Whitlow WD, et al. Diagnosis of acute cerebral infarction: comparison of CT and MR imaging. AJNR 1991; 12: 611-620. (Prospective study cohort of 31 patients – Level II/III evidence) 9. Lev MH, Farkas J, Gemmete JJ, et al. Acute stroke: improved nonenhanced CT detection - benefits of soft-copy interpretation by using variable window width and center level settings. Radiology 1999; 213: 150-155. (Retrospective study 21 patients – Level IV evidence) 10. Gonzalez G, Schaefer PW, Buananno FS, et al. Diffusion-weighted MRI imaging: diagnostic accuracy in patients imaged within 6 hours of stroke symptom onset. Radiology 1999; 210: 155-162. (Retrospective study blinded review of 22 patients – Level III evidence) 11. Mullins ME, Schaefer PW, Sorensen AG, et al. CT and conventional and diffusion- weighted MR imaging in acute stroke: study in 691 patients at presentation to the emergency department. Radiology 2002; 224: 353-360. (Retrospective study cohort of 691 patients – Level II evidence) 12. Lansberg MG, Albers GW, Beaulieu C, et al. Comparison of diffusion-weighted MRI and CT in acute stroke. Neurology 2000; 54: 1557-1561. (Prospective study 19 patients – Level III evidence) 13. Van Everdingen KJ, van der Grond J, Kappelle LJ, et al. Diffusion-weighted magnetic resonance imaging in acute stroke. Stroke 1998; 29: 1783-1790. (Prospective study 42 patients – Level II evidence) 14. Barber PA, Darby DG, Desmond PM, et al. Identification of major ischemic change: diffusion weighted imaging versus computed tomography. Stroke 1999; 30: 2059- 2065. (Prospective study 17 consecutive patients – Level III evidence) 15. Nederkoorn PJ, Mali WPM, Eikelboom BC, et al. Preoperative Diagnosis of Carotid Artery Stenosis: Accuracy of Noninvasive Testing. Stroke 2002; 33: 2003-2008. (Prospective study 350 consecutive patients – Level II evidence) 16. Kent KC, Kuntz KM, Patel MR, et al. Perioperative imaging strategies for carotid : an analysis of morbidity and cost-effectiveness in symptomatic patients. JAMA 1995; 274: 888-893. (Decision analysis - Level III evidence) 17. Kapral MK, Silver FL, with the Canadian Task Force on Preventive Health Care. Preventive Health care, 1999 update: 2. Echocardiography for the detection of a cardiac source of embolus in patients with stroke. CMAJ 1999; 161(8): 989-996.

66 18. Rother J, Wentz KU, Rautenberg W, et al. Magnetic resonance angiography in vertebrobasilar ischaemia. Stroke 1993; 24: 1310-1315. (Cohort of 41 patients – Level III evidence) 19. Castillo M, Falcone S, Naidich TP, et al. Imaging in acute basilar artery thrombosis. Neuroradiology 1994; 36: 426-429. (Retrospective study 11 case controls – Level IV evidence)

Further Reading 1. Davenport R, Dennis M. Neurological emergencies: acute stroke. J Neurol Neurosurg Psychiatry 2000; 68: 277-288. 2. Jager HR. Diagnosis of stroke with advanced CT and MR imaging. British Medical Bulletin 2000; 56: 318-333. 3. Keir SL, Warlaw JM. Systematic review of diffusion and perfusion imaging in acute ischemic stroke. Stroke 2000; 31: 2723-2731.

67 TRANSIENT ISCHAEMIC ATTACKS

CRANIAL COMPUTED TOMOGRAPHY (CT) • Initial imaging modality of choice in the evaluation of a patient with transient ischaemic attacks. 1 • May reveal an area of brain infarction appropriate to TIA symptoms in 15-30% of patients (which may influence subsequent management, especially the timing of an eventual ). 2, 3 • Allows exclusion of rare lesion such as subdural haematoma or brain tumour responsible for symptoms. 4, 5

CAROTID DOPPLER ULTRASONOGRAPHY • Screening modality of choice for the study of vessels involved in causing symptoms of transient ischaemic attacks. 6, 7 • ~87% sensitivity and ~75% specificity in identifying severe internal carotid artery stenosis. 7, 8 • Advantages: non-invasive, relatively inexpensive and widely available.

68 MAGNETIC RESONANCE ANGIOGRAPHY (MRA) • ~92% sensitivity and ~75% specificity for the detection of severe internal carotid artery stenosis. 7 • Improved sensitivity (96%) and specificity (80%) when MRA and carotid Doppler ultrasound results are combined. 7 • A strategy using combination of carotid Doppler US and MRA, reserving Digital Subtraction Angiography (DSA) for incongruent results, has been found to maximise quality adjusted life expectancy, and was cost effective alternative to using DSA alone. 6 • More recent studies support the use of contrast enhanced MRA as a diagnostic alternative to DSA in the preoperative evaluation of patients prior to carotid endarterectomy. 9-12 • Advantages: non-invasive, relatively less expensive and safer than angiography. • Limitations: 1 • Over-represents arterial stenosis, especially in high grade narrowing. • Carotid atheromatous ulceration is not reliably visualised.

COMPUTED TOMOGRAPHIC ANGIOGRAPHY (CTA) • New emerging modality (multi-slice helical imaging), with high sensitivity and specificity, for detection of severe internal carotid artery stenosis. 12-14 • May supplant the role of MRA in the evaluation of carotid artery stenosis. 12

DIGITAL SUBTRACTION ANGIOGRAPHY (DSA) • “Gold Standard” for the evaluation of carotid artery disease. 7 • Endarterectomy of the symptomatic carotid artery is indicated in surgically tolerant patients with carotid stenosis greater or equal to 70%. 15, 16 • Endarterectomy in patients with symptomatic moderate carotid stenosis of 50-69% offers a moderate reduction in the risk of stroke. Decision about treatment in these patients should take into account recognised risk factors and complication rate of surgery. 17, 18 • Patients with <50% stenosis do not benefit from surgery and should be managed medically. 17 • Disadvantages of DSA: expensive, invasive procedure with potential risks and complications (0.5-2.0% risk of stroke). 19

69 REFERENCES 1. Culebras A, Kase CS, Masdeu JC, et al. Practice guidelines for the use of imaging in transient ischemic attacks and acute stroke: a report of the stroke council, American Heart Association. Stroke 1997; 28: 1480-1497. (Level II evidence) 2. Dennis M, Blamford J, Sandercock P, et al. Computed tomography in patients with transient ischaemic attacks: when is a transient ischaemic attack not a transient ischaemic attack but a stroke? J Neurol 1990; 237: 257-261. (Prospective study cohort of 120 patients – Level II/III evidence) 3. Evans GW, Howard G, Murros KE, et al. Cerebral infarction verified by cranial computed tomography and prognosis for survival following transient ischemic attacks. Stroke 1991; 22: 431-436. (Retrospective study cohort of 350 patients – Level III evidence) 4. Williams RS. Chronic subdural hematoma simulating transient ischemic attacks. Ann Neurol 1979; 5: 597. (Case report – Level IV evidence) 5. Ross RT. Transient tumor attacks. Ann Neurol 1983; 40: 633-636. 6. Kent KC, Kuntz KM, Patel MR, et al. Perioperative imaging strategies for carotid endarterectomy: an analysis of morbidity and cost-effectiveness in symptomatic patients. JAMA 1995; 274: 888-893. (Decision analysis - Level III evidence) 7. Nederkoorn PJ, Mali WPTM, Eikelboom BC, et al. Preoperative diagnosis of carotid artery stenosis: accuracy of noninvasive testing. Stroke 2002; 33: 2003-2008. (Prospective study 350 consecutive patients – Level II evidence) 8. Blakeley DD, Oddone EZ, Hasselblad V, et al. Noninvasive carotid artery testing: a meta-analytic review. Ann Intern Med 1995; 122: 360-367. (Meta-analysis – Level II evidence) 9. Remonda L, Senn P, Barth A, et al. Contrast-enhanced 3D MR angiography of the carotid artery: comparison with conventional digital subtraction angiography. AJNR 2002; 23: 213-219. (Cohort of 120 consecutive patients – Level II evidence) 10. Westwood ME, Kelly S, Berry E, et al. Use of magnetic resonance angiography to select candidates with recently symptomatic carotid stenosis for surgery: systematic review. BMJ 2002; 324: 1-5. (Systematic review – Level III evidence) 11. Huston III J, Fain SB, Wald JT, et al. Carotid artery: elliptic centric contrast- enhanced MR angiography compared with conventional angiography. Radiology 2001; 218: 138-143. (Prospective study 50 consecutive patients – Level II evidence) 12. Radoux B, Marro B, Koskas F, et al. Carotid artery stenosis: prospective comparison of CT, three-dimensional gadolinium-enhanced MR, and conventional angiography. Radiology 2001; 220: 179-185. (Prospective study 22 patients – Level III evidence) 13. Leclerc X, Godefroy O, Lucas C, et al. Internal carotid arterial stenosis: CT angiography with volume rendering. Radiology 1999; 210: 673-682. (Prospective study 22 consecutive patients – Level III evidence) 14. Anderson GB, Ashforth R, Steinke DE, et al. CT angiography for the detection and characterization of carotid artery bifurcation disease. Stroke 2000; 31: 2168-2173. (Prospective study 40 patients – Level II/III evidence) 15. North American Symptomatic Carotid Endarterectomy Trial Collaborators. Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. NEJM 1991; 325: 445-453. (Level I evidence) 16. European Carotid Surgery Trialists’ Collaborative Group. Randomised trial of endarterectomy for recently symptomatic carotid stenosis: final results of the MRC European carotid surgery trial (ECST). Lancet 1998; 351: 1379-1387. (Randomised controlled trial - Level I evidence) 17. Barnett HJM, Taylor DW, Eliasziw M, et al, for the North American Symptomatic Carotid Endarterectomy Trial Collaborators. Benefit of carotid endarterectomy in

70 patients with symptomatic moderate or severe stenosis. NEJM 1998; 339: 1415- 1425. (Randomised controlled trial - Level I evidence) 18. Cina CS, Clase CM, Haynes RB. Carotid endarterectomy for symptomatic carotid stenosis. Cochrane Database of systematic Review 2000; (3). CD 001081. 19. Heiserman JE, Dean BL, Hodak JA, et al. Neurologic complications of . AJNR 1994; 15: 1401-1407. (Prospective study 680 consecutive procedures – Level II evidence)

Further Reading 1. Barnett HJM, Meldrum HE, Eliasziw M, for the North American Symptomatic Carotid Endarterectomy Trial (NASCET) collaborators. The appropriate use of carotid endarterectomy. CMSJ 2002; 166(9): 1169-1179.

71 CHRONIC SINUSITIS

CHRONIC SINUSITIS • Chronic sinusitis is a clinical diagnosis and is defined as a rhinosinusitis lasting >12 weeks that includes two or more major sinus symptoms or atleast one major and two minor sinus symptoms with or without findings on physical examination.1 • Major symptoms: facial pain/pressure, facial congestion/fullness, nasal obstruction/blockage, nasal discharge, hyposmia/anosmia, purulence in the nasal cavity on examination and fever (acute rhinosinusitis only). 1 • Minor symptoms: headache, fever (all nonacute), halitosis, fatigue, dental pain, cough and ear pain/pressure/fullness. 1 • Imaging is indicated only after adequate medical treatment. ~30% of asymptomatic patients show incidental mucosal changes on CT in adults. Therefore, imaging should be interpreted in the light of history, endoscopic examination and response to medical treatment. 2, 3 • Plain radiography has limited value for imaging paranasal sinuses, especially the ethmoid sinuses and the ostiomeatal complex and routine use is not indicated. 4, 5, 8

CORONAL NON-CONTRAST COMPUTED TOMOGRAPHY • Imaging modality of choice for evaluation of chronic sinusitis. 5-10 • Coronal plane optimally displays: 5,11 • The ostiomeatal unit and relationship of the brain and roof of the ethmoid sinus. • The relationship of the orbits to the paranasal sinuses. • Useful in: 2,5 • Delineating the anatomy and pattern of the inflammatory paranasal disease prior to surgery. • The diagnosis of atypical sinus infections and malignancy. • The management of the complications of rhinosinusitis. • Findings in chronic rhinosinusitis are diverse which include mucosal thickening, air fluid levels, and complete sinus opacification. 5 • Although CT provides information about the extent of mucosal disease, several studies have failed to correlate CT findings with symptom severity at the time of presentation. 12, 13

72 • A recent study reports the association of presence of CT disease with higher patient symptom scores compared with symptom scores of patients without CT disease. 14 • CT findings may predict improvement in symptoms of sinusitis after treatment (larger improvement and lower absolute levels of symptom severity after treatment in patients with more severe CT findings). 15 • Contrast material is used: 16 • When the evaluation of coronal CT suggests a mass within the sinonasal cavities. • When intracranial complications of sinonasal infections (eg. subperiosteal, intradural, and brain abscesses) or thrombosis of ophthalmic veins or dural sinuses such as cavernous sinuses are suspected. • Magnetic resonance imaging is useful in the evaluation of complicated sinusitis, intraorbital and intracranial manifestations of aggressive sinusitis, and sinonasal neoplasms. 5, 17

73 REFERENCES 1. Lanza DC, Kennedy DW. Adult rhinosinusitis defined. Otolaryngol Head Neck Surg 1997; 117(3): S1-S7. 2. Jones NS. CT of the paranasal sinuses: a review of the correlation with clinical, surgical and histopathological findings. Clin Otolaryngol 2002; 27: 11-17. (Review) 3. MacLennan A, MacGarry GW. Diagnosis and management of chronic sinusitis. BMJ 1995; 310: 529. 4. Konen E, Faibel M, Kleinbaum Y, et al. The value of the occipitomental (Water’s) view in diagnosis of sinusitis: a comparative study with computed tomography. Clinical Radiology 2000; 55: 856-860. (Prospective study 134 patients – Level II/III evidence) 5. Yousem DM. Imaging of sinonasal inflammatory disease. Radiology 1993; 188: 303-314. 6. Roberts DN, Hampal S, East CA, et al. The diagnosis of inflammatory sinonasal disease. J Laryngol Otol 1995; 109: 27-30. (Prospective study 25 consecutive patients – Level III evidence) 7. Laine FJ, Smorker WRK. The ostiomeatal unit and endoscopic surgery: anatomy, variations and imaging findings in inflammatory disease. AJR 1992; 159: 849-857. (Review) 8. Davidson TM, Brahme FJ, Gallagher ME. Radiographic evaluation of nasal dysfunction: computed tomography versus plain films. Head Neck 1989; 11: 405- 409. (Cohort of 62 patients – Level III evidence) 9. Goodman GM, Martin DS, Klein J, et al. Comparison of a screening coronal CT versus a contiguous coronal CT for the evaluation of patients with presumptive sinusitis. Ann Asthma Immunol 1995; 74: 178-182. 10. Bhattacharyya N. Test-retest reliability of computed tomography in the assessment of chronic rhinosinusitis. Largyngoscope 1999; 109: 1055-1058. (Prospective study 45 consecutive patients – Level II/III evidence) 11. Zinreich SJ. Rhinosinusitis: radiologic diagnosis. Otolaryngol Head Neck Surg 1997: 117(3): S27-S34. 12. Bhattacharya T, Piccirollo J, Wippold FJ II. Relationship between patient-based descriptions of sinusitis and paranasal sinus computed tomographic findings. Arch Otolaryngol Head Neck Surg 1997; 123: 1189-1192. (Prospective study 586 consecutive referrals for sinus CT – Level II evidence) 13. Stewart MG, Sicard MW, Piccirillo JF, et al. Severity staging in chronic sinusitis: are CT scan findings related to patients symptoms? Am J Rhinol 1999; 13: 161-167. (Prospective data from two academic centers 254 patients – Level II/III evidence) 14. Arango P, Kountakis SE. Significance of computed tomography pathology in chronic rhinosinusitis. Laryngoscope 2001; 111: 1779-1782. (Prospective study 53 consecutive patients – Level II evidence) 15. Stewart MG, Donovan DT, Parke RB, et al. Does the severity of sinus computed tomography findings predict outcome in chronic sinusitis? Otolaryn Head Neck Surg 2000; 123: 81-84. (Prospective data, non-randomised – Level III evidence) 16. Mafee MF, Chow JM, Meyers R. Functional endoscopic sinus surgery: anatomy, CT screening, indications, and complications. AJR 1993; 160: 735-744. 17. Younis RT, Anand VK, Davidson B. The role of computed tomography and magnetic resonance imaging in patients with complications. Laryngoscope 2002; 112: 224-229. (Retrospective case control study of 82 adult and paediatric patients – Level IV evidence)

74 Further Reading 1. Zeifer B. Update on sinonasal imaging: anatomy and inflammatory disease. Neuroimaging Clinics of North America 1998; 8(3): 607-60.

75 SALIVARY GLAND SWELLING

ULTRASONOGRAPHY (US) • Initial imaging modality of choice for evaluation of suspected salivary gland masses and inflammatory disease of the salivary glands. 1, 2 • Allows: • Detection of sialolithiasis. 1-3 • Differentiation of benign from malignant masses. 2 • Distinction of intraglandular lesions from extraglandular lesions (98% accuracy). 2 • Confirmation of diagnosis of abscess or sialectasia. 2 • Advantages: • Relatively inexpensive. • Safe (non-invasive and does not involve use of ionising radiation or contrast medium). • Widely available. • Limitations: 2 • Inability to evaluate deep parotid masses, lesions obscured by the mandible, parapharyngeal and deep neck adenopathy, and the intracranial or skull base extent of a mass. • Lacks specificity for cystic lesions. • Difficult to demonstrate relationship of a tumour to the facial nerve to the surgeons.

COMPUTED TOMOGRAPHY (CT) • Useful in the evaluation of inflammatory masses of the salivary glands. 4 -6 • Superior to plain radiographs and US in detection of sialolithiasis. 7 • Allows detection and assessment of extent of salivary gland tumours. 5, 6, 9 • Helpful in the differential diagnosis of salivary gland tumours. 8 • Limitations: • Malignant tumour may mimic a benign tumour on CT scan. 5 • Moderate accuracy (60-70%) in predicting the histological diagnosis of a lesion. 9

76 MAGNETIC RESONANCE IMAGING (MRI) • Demonstrates the presence, extent, margins, and internal architecture of minor salivary gland tumours. 10 • Superior to CT: • As a diagnostic tool for the detection of minor salivary gland tumours. 10 • In demonstrating perineural, meningeal, and skull base invasion. 4 • Symptoms such as the presence of cranial nerve palsies, meningeal signs, venous obstruction, and fixation of the mass to vital structures such as the carotid artery may lead to preference for MRI over CT. 4 • Limitations: inability to detect small calcifications.

CONVENTIONAL/DIGITAL • Most detailed way to image the salivary ductal system. 3, 11, 12 • Disadvantages: 11 • Invasive procedure with a risk of complications such as damage to the orifice, overfilling and rupture of the ductal system, exacerbation of infection, and adverse reaction to contrast material. • Exposure to ionising radiation. • Need for experienced operator to cannulate the small, often oedematous ductal orifices. • Pain during retrograde injection of contrast material (minimise with fluoroscopic screening). • Contraindicated in acute salivary infection.

MAGNETIC RESONANCE SIALOGRAPHY • Non-invasive alternative to conventional/digital sialography. 3, 4, 13 • Allows accurate assessment of salivary gland calculi and stenoses. 13 • Advantages: • Non-invasive. • No exposure to ionising radiation. • Does not require use of contrast material. • Limitations: 4 • False negative readings may occur in patients with very small calculi that are causing no ductal dilatation. • Inability to distinguish solid calculi from inspissated mucus and/or debris. • Distortion artefacts caused by dental amalgam may impair visualisation of calculi or stenoses near the main ductal orifice. • Disadvantages: • Expensive. • Limited availability.

FINE NEEDLE ASPIRATION/ BIOPSY (FNAB) • Allows accurate differentiation between benign and malignant tumours of salivary glands. 14, 15 • Limitations: inflammatory masses of the salivary glands may mimic epithelial neoplasms at cytology. 14, 15

77 REFERENCES 1. Murray ME, Buckenham TM, Joseph AEA. The role of ultrasound in screening patients referred for sialography: a possible protocol. Clin Otolaryngol 1996; 21: 21- 23. (Prospective study 31 consecutive patients – Level III evidence) 2. Gritzmann N. Sonography of the salivary glands. AJR 1989; 153: 161-166. (Retrospective study cohort of 849 patients – Level III evidence) 3. Jager L, Menauer F, Holzknecht N, et al. Sialolithiasis: MR sialography of the submandibular duct – an alternative to conventional sialography and US? Radiology 2000; 216: 665-671. (Prospective blinded study 24 consecutive patients – Level II evidence) 4. Yousem DM, Kraut MA, Chalian AA. Major salivary gland imaging. Radiology 2000; 216: 19-29. 5. Casselman JW, Mancuso AA. Major salivary gland masses: comparison of MR imaging and CT. Radiology 1987; 165: 183-189. (Prospective study 21 patients – Level III evidence) 6. Bryan RN, Miller RH, Ferreyro RI, et al. Computed tomography of the major salivary glands. AJR 1982; 139: 547-554. (Cohort of 48 patients – Level III evidence) 7. Avrahami E, Englender M, Chen E, et al. CT of submandibular gland sialolithiasis. Neuroradiology 1996; 38: 287-290. (Prospective study cohort of 76 patients – Level II/III evidence) 8. Choi DS, Na DG, Byun HS, et al. Salivary gland tumors: evaluation with two-phase helical CT. Radiology 2000; 214: 231-236. (Prospective study cohort 64 patients – Level II/III evidence) 9. Berg HM, Jacobs JB, Kaufman D, et al. Correlation of fine needle aspiration biopsy and CT scanning of parotid masses. Laryngoscope 1986; 96: 1357-1362. (Retrospective study cohort of 42 patients – Level III evidence) 10. Kaneda T, Minami M, Ozawa K, et al. Imaging tumors of the minor salivary glands. Oral Surg Oral Med Oral Pathol 1994; 77: 385-390. (Retrospective study 9 case controls – Level IV evidence) 11. Silvers AR, Som PM. Salivary glands. Radiologic Clin N America 1998; 36(5): 941-966. (Review) 12. Buckenham TM, George CD, McVicar D, et al. Digital sialography: imaging and intervention. Br J Radiology 1994; 67: 524-529. (Cohort of 109 patients – Level II/III evidence) 13. Becker M, Marchal F, Becker CD, et al. Sialolithiasis and salivary ductal stenosis: diagnostic accuracy of MR sialography with a three-dimensional extended-phase conjugate-symmetry rapid spin-echo sequence. Radiology 2000; 217: 347-358. (Prospective study 67 consecutive patients – Level II evidence) 14. Sack MJ, Weber RS, Weinstein GS, et al. Image-guided fine-needle aspiration of the head and neck: five years’ experience. Arch Otolaryngol Head Neck Surg 1998; 124: 1155-1161. (Retrospective cohort of 109 patients – Level III evidence) 15. Yousem DM, Sack MJ, Weinstein GS, et al. Computed tomography-guided aspirations of parapharyngeal and skull base masses. Skull Base Surg 1995; 5: 131- 136. (Cohort of 22 patients – Level III evidence)

78 TINNITUS

TINNITUS • Tinnitus, a buzzing or ringing in the ear, may be pulsatile or continuous (non- pulsatile). 1 • Pulsatile tinnitus suggests the presence of vascular abnormality (a tumour, a congenital anomaly, a malformation, or an acquired vasculopathy). 1 • Patients with non-pulsatile tinnitus may require exclusion of cerebellopontine angle tumour, most often a vestibular schwannoma. 1 • The distinction, with a detailed clinical evaluation, determines the most appropriate imaging study. 1-3 • In vast majority, no pathology is identified. 1-3

COMPUTED TOMOGRAPHY (CT) • Contrast-enhanced CT scan of the temporal and brain is the imaging modality of choice for investigation of pulsatile tinnitus. 1-4 • Allows delineation of the bony abnormalities that are associated with some of the vascular diseases and paragangliomas. 4 • Useful in delineation of the location and size of the jugular bulb and the course of the carotid artery in order to exclude an aberrant carotid artery or a vascular mass of the middle ear. 3 • Most neoplasms and anomalies are best seen on bone algorithm CT studies. 1 • Superior to MRI in delineating the anatomical extent of the vascular tumours/paragangliomas. 1 • Advantages: relatively inexpensive and widely available. 79 • Limitations: ionising radiation and use of contrast agent.

MAGNETIC RESONANCE IMAGING IN THE EVALUATION OF NON- PULSATILE TINNITUS • Gadolinium enhanced MRI (with thin transverse and coronal T1- and T2- weighted images through the temporal bones, and transverse images through the entire brain) is the study of choice for evaluation of non-pulsatile tinnitus. 1-2 • Helps exclude a vestibular schwannoma or other neoplasm of the cerebellopontine angle cistern in patients with non-pulsatile tinnitus. 1-2 • Limitations: limited availability and high expense.

MAGNETIC RESONANCE IMAGING (MRI/MRA) IN THE EVALUATION OF PULSATILE TINNITUS • Indications: • To evaluate patients with objective tinnitus or severe subjective tinnitus with or without otoscopic abnormality and normal CT scan findings. 5 • To delineate an abnormality detected on CT. • To detect rare causes of pulsatile tinnitus such as multiple sclerosis and a chiari I malformation not seen on CT. 1 • Addition of MRA to conventional MRI greatly enhances the ability to show vascular lesions. 5 • Superior to CT for enhancement of vascular tumours, typically paragangliomas. 6, 7 • Limitations: • Low yield in patients with subjective pulsatile tinnitus and a normal otoscopic examination. 5 • May not detect dural fistulas. 8

ANGIOGRAPHY • Indicated when there is high clinical suspicion of dural arterio-venous malformation or fistula and the cross-sectional imaging studies (CT and MRI) are normal. 4, 9

80 REFERENCES 1. Weissman JL, Hirsch BE. Imaging of tinnitus: a review. Radiology 2000; 216: 342- 349. (Review) 2. Marsot-Dupuch K. Pulsatile and nonpulsatile tinnitus: a systemic approach. Seminars in US, CT, and MRI 2001; 22(3): 250-270. (Review) 3. Sismanis A. Pulsatile tinnitus: a 15-year experience. American J Otol 1998; 19: 472- 477. (Cohort of 145 patients – Level II/III evidence) 4. Remley KB, Coit WE, Harnsberger HR, et al. Pulsatile tinnitus and the vascular tympanic membrane: CT, MR and angiographic findings. Radiology 1990; 174: 383-389. (Retrospective study cohort of 107 patients – Level III evidence) 5. Dietz RR, Davis WL, Harnsberger HR, et al. MR imaging and MR angiography in the evaluation of pulsatile tinnitus. AJNR 1994; 15: 879-889. (Cohort of 49 patients – Level III evidence) 6. Olsen WL, Dillon WP, Kelly WM, et al. MR imaging of paragangliomas. AJNR 1986; 7: 1039-1042. (Retrospective study 15 paragangliomas in 10 patients – Level IV evidence) 7. Vogl T, Bruning R, Schedel H, et al. Paragangliomas of the jugular bulb and carotid body: MR imaging with short sequences and Gd-DTPA enhancement. AJNR 1989; 10: 823-827. (Cohort of 26 patients – Level III evidence) 8. DeMarco JK, Dillon WP, Halbach VV, et al. Dural arteriovenous fistulas: evaluation with MR imaging. Radiology 1990; 175: 193-199. (Retrospective study 12 case controls – Level IV evidence) 9. Shin EJ, Lalwani AK, Dowd CF. Role of angiography in the evaluation of patients with pulsatile tinnitus. Laryngoscope 2000; 110:1916-1920. (Retrospective study cohort of 87 patients – Level III evidence)

Further Reading 1. Lockwood AH, Salvi RJ, Burkard RF. Current concepts: Tinnitus. NEJM 2002; 347(12): 904-910. 2. Willinsky RA. Tinnitus: imaging algorithms. Can Assoc Radiol J 1992; 43: 93-99.

81 OSTEOPOROSIS AND BONE DENSITOMETRY

OSTEOPOROSIS AND BONE MINERAL DENSITY (BMD) • Radiographic evidence of minimally traumatic fracture, especially vertebral or hip fracture, is a presumptive indication of osteoporosis. 1,2 • Formal diagnosis of osteoporosis is based on the assessment of bone mineral density (BMD). Current definition of osteoporosis is T-score less than –2.5. 1 • The risk of osteoporotic fracture increases with decreasing bone mineral density. However, age, presence of previous fractures and postural instability also contribute to fracture risk. 2,3 • Each standard deviation reduction in BMD increases the age-adjusted risk of fracture by a factor of about two. 3 • The availability of effective therapies for osteoporosis has now made such assessment worthwhile. 1

DUAL-ENERGY X-RAY ABSORPTIOMETRY (DEXA SCAN) • The current “gold standard” for the diagnosis of osteoporosis. 1 • DEXA is superior to other techniques for assessing BMD because of its: 4 • Low precision error. • Low radiation dose. • Capacity to measure multiple skeletal sites. • Bone densitometry reports provide a “T-score” (representing the number of standard deviations from the young normal mean BMD) or a “Z-score” (number of standard deviations from the age-related mean BMD). 5 • Based on bone densitometry, measured by DEXA and the T-score , the World Health Organization classifies the patients into three categories: 6,7 1. Normal bone density: T-score greater than –1. 2. Osteopenia (low bone mass): T-score between –1 and –2.5. 3. Osteoporosis: T-score less than –2.5. • BMD measurement should only be done if the decision to treat (or not to treat) is influenced by the result of the test. Thus, it is a valid and essential investigation in patients at high risk of osteoporotic fracture who seek medical advice, but not justified for screening a population of healthy people. 1,7

INDICATIONS FOR DEXA SCAN • The main high risk groups for whom BMD measurement should be considered include: 1 1. History of minimally traumatic fracture (especially hip and spine fractures). 2. Premature menopause in females either natural or iatrogenic. 3. Conditions or therapy associated with glucocorticoid excess. 4. Established secondary causes such as hypogonadism, hyperparathyroidism, thyrotoxicosis, chronic renal failure, myeloma, rheumatoid arthritis, etc. 5. Monitoring therapy. 6. Family history of osteoporosis. • Items 1-5 are medicare rebatable. 8

82 REFERENCES 1. Sambrook PN, Seeman E, Phillips SR, et al. Preventing osteoporosis: outcome of the Australian Fracture Prevention Summit. MJA 2002; 176: S1-S16. 2. Cummings SR, Nevitt MC, Browner WS, et al. Risk factors of hip fracture in white women. NEJM 1995; 332: 767-773. (Prospective study 9516 white women – Level I/II evidence) 3. Marshall D, Johnell O, Wedel H. Meta-analysis of how well measures of bone mineral density predict occurrence of osteoporotic fractures. BMJ 1996; 312: 1254- 1259. (Systematic review / meta-analysis of prospective cohort studies – Level II evidence) 4. Genant HK. Current state of bone densitometry for osteoporosis. Radiographics 1998; 18: 913-918. 5. Blake GM, Fogelamn I. Applications of bone densitometry for osteoporosis. Endocrinol Metab Clin North Am 1998; 27: 267-288. 6. Kanis JA. Assessment of fracture risk and its application to screening for postmenopausal osteoporosis: a synopsis of a WHO report. WHO Study Group. Osteoporosis Int 1994; 4: 368-381. 7. Assessment of fracture risk and its application to screening for post menopausal osteoporosis: a report of WHO Study Group. Geneva, Switzerland: World Health Organization, 1994. (WHO technical series 843). 8. Medicare Benefits Schedule Book. Canberra: Commonwealth Department of Aged Care, 2001.

Further Reading 1. South-Paul J. Osteoporosis: Part I. Evaluation and assessment. American Family Physician 2001; 63(5): 897-904.

83 INCIDENTAL ADRENAL MASS ON CT

INCIDENTAL ADRENAL MASS • Imaging phenotype and mass size are the two major predictors of malignancy in incidental adrenal lesions. 1 • Incidental adrenal adenomas are found in up to 5% of CT scans. 1

COMPUTED TOMOGRAPHY • Primary imaging modality for characterisation of adrenal masses. 1 • Lesions >5cm in size are likely to be malignant and these patients should be referred for surgery. 1-3 • Unenhanced CT attenuation values are useful in distinguishing benign from malignant lesions: 4, 5 1. Lesions of 0 HU or less can be regarded, as benign (47% sensitivity and 100% specificity) and further work-up is not required. 3, 6, 7 2. Lesions with a density >20 HU are likely malignant and should be biopsied when the result influences management.

84 3. For CT indeterminate lesions (0-20 HU), chemical shift MRI should be performed to further characterise the adrenal mass. • Delayed contrast enhanced CT can be performed if non-contrast CT is indeterminate. 8 • Follow up CT can be used to monitor lesions that are at low risk of malignancy based on their small size and absence of known primary malignancy. 3 • Lesions that are unchanged or smaller in size on CT are left alone, whereas lesions that increase in size are excised. 3

CHEMICAL SHIFT MAGNETIC RESONANCE IMAGING (MRI) • Useful for imaging of CT-indeterminate adrenal lesions. 4, 5 • Non-invasive alternative to image guided percutaneous biopsy for evaluating adrenal masses in patients with known primary malignancy. 9 • ~93% accuracy for differentiating benign from malignant adrenal masses. 10 • Benign adrenal cortical adenomas lose signal on out-of-phase images but appear relatively bright on in-phase images. 11

ADRENAL BIOPSY • >90% accuracy for malignant lesions when adequate sample available. 12, 13 • Most useful in patients with known extra-adrenal malignancies who are at risk for adrenal metastases. 14, 15 • Primarily used to distinguish adrenal from non adrenal tissues (eg metastases) or infection. 1 • Limitations: 12, 13 • Difficult interpretation in benign processes. • Potential complications (pneumothorax, bleeding, tumour tracking, infection, adrenal abscess formation) • Nondiagnostic rate ~ 15%.

85 REFERENCES 1. Young WF Jr. Management approaches to adrenal incidentalomas. Endocrinology and Metabolism Clinics of North America 2000; 29(1): 159-185. 2. Herrera MF, Grant CS, van Heerden JA, et al. Incidentally discovered adrenal tumours: an institutional perspective. Surgery 1991; 110(6): 1014-1021. 3. Barry MK, van Heerden JA, Farley DR, et al. Can adrenal incidentalomas be safely observed? World J Surg 1998; 22: 599-604. ( Retrospective cohort study of 231 patients – Level III evidence) 4. McNicholas MM, Lee MJ, Mayo-Smith WW, et al. An imaging algorithm for the differential diagnosis of adrenal adenomas and metastases. AJR 1995; 165: 1453- 1459. (Cohort of 33 patients - Level III evidence) 5. Pender SM, Boland GW, Lee MJ, et al. The incidental nonhyperfunctioning adrenal mass: an imaging algorithm for characterisation. Clinical Radiology 1998; 53: 796- 804. 6. Lee MJ, Hahn PF, Papanicolaou N, et al. Benign and malignant adrenal masses: CT distinction with attenuation coefficients, size, and observer analysis. Radiology 1991; 179: 415-418. (Retrospective study cohort of 107 consecutive patients – Level III evidence) 7. Boland GWL, Lee MJ, Gazelle GS, et al. Characterization of adrenal masses using unenhanced CT: an analysis of the CT literature. AJR 1998; 171: 201-204. (Level II evidence) 8. Caoilli EM, Korobkin M, Francis IR, et al. Adrenal masses: characterization with combined unenhanced and delayed enhanced CT. Radiology 2002; 222: 629-633. (Prospective study 162 consecutive adrenal masses – Level II/III evidence) 9. Schwartz LH, Panicek DM, Doyle MV, et al. Comparison of two algorithms and their associated charges when evaluating adrenal masses in patients with malignancies. AJR 1997; 168: 1575-1578. (Retrospective study 54 patients with known malignancies – Level III evidence) 10. Heinz- Peer G, Honigschnabl S, Schneider B, et al. Characterization of adrenal masses using MR imaging with histopathologic correlation. AJR 1999; 173: 15-22. (Prospective study 114 consecutive patients – Level II evidence) 11. Lee MJ, Mayo-Smith WW, Hahn PF, et al. State-of–the-art MR imaging of the adrenal gland. Radiographics 1994: 14: 1015. 12. Welch TJ, Sheedy PF, Stephens DH, et al. Percutaneous adrenal biopsy: review of a 10-year experience. Radiology 1994; 193: 341-344. (Retrospective study 277 adrenal biopsies – Level III evidence) 13. Silverman SG, Mueller PR, Pinkney LP, et al. Predictive value of image-guided adrenal biopsy: analysis of results of 101 biopsies. Radiology 1993; 187:715-718. (Retrospective study 97 patients – Level III/IV evidence) 14. Candel AG, Gattuso P, Reyes CV, et al. Fine needle aspiration biopsy of adrenal masses in patients with extra-adrenal malignancy. Surgery 1993; 114(6): 1132-1137. (Retrospective study 39 patients – Level III evidence) 15. Graham DJ, Mc Henry CR. The adrenal incidentaloma: guidelines for evaluation and recommendations for management. Surg Oncology Clinics of North America 1998; 7: 749-764.

Further Reading 1. Teeger S, Papanicolaou N, Vaughan ED Jr. Current concepts in imaging adrenal masses. World J Urol 1999; 17: 3-8. 2. Barzon L, Boscaro M. Diagnosis and management of adrenal incidentalomas. J Urology 2000; 163: 398-407.

86 INVESTIGATION OF CUSHING’S SYNDROME

CAUSES OF CUSHING’S SYNDROME (CS) • Cushing’s disease (excessive production of ACTH) is the most common aetiology, accounting for 65-75% of Cushing’s syndrome (CS). Most cases of Cushing’s disease are result of pituitary adenomas. 1 • Ectopic production of ACTH from a variety of tumours (bronchial carcinoid, thymoma, oat-cell carcinoma, phaeochromocytoma, islet cell tumour, and prostate cancer) accounts for 10-15% of CS. 1 • Primary adrenocortical disease accounts for the remaining 20-30% of CS, including benign adenoma (10-15%), adrenocortical carcinoma (5-10%), and adenomatous hyperplasia (5%). 1

BIOCHEMICAL TESTS • Once Cushing’s syndrome is confirmed biochemically, imaging is directed by the measurement of ACTH levels. 1-4 • Imaging is used for localisation of pituitary or ectopic corticotropin-secreting tumours and adrenal masses and should only be undertaken after a biochemical diagnosis has been made because substantial numbers of general population have asymptomatic non-secreting microadenomas revealed by imaging. 2, 5 • When the ACTH level is normal or mildly elevated, pituitary disease is the most likely diagnosis and MRI of the pituitary is indicated. 1-4 • A low or undetectable level of ACTH suggests primary adrenocortical disease, and in such cases, CT of the adrenals is the investigation of choice. 1-4 • When the biochemistry data suggest the presence of ectopic ACTH syndrome, a CT scan of the abdomen and chest should be performed as the initial radiographic evaluation for the variety of tumours responsible for this syndrome. 1-4

PITUITARY IMAGING • Magnetic resonance imaging (MRI) is the imaging modality of choice for localisation of pituitary adenoma in pituitary-dependent Cushing’s disease (53-75% sensitivity for detecting corticotroph tumour). 5-9 • MRI, with the addition of gadolinium, facilitates diagnosis of microadenoma and increases the confidence with which cavernous sinus invasion can be diagnosed or excluded. 9, 10

87 • Advantages of MRI: superior soft tissue resolution (depicts the anatomy of the pituitary gland, infundibulum, optic chiasm, cavernous sinuses and neighbouring vascular structures accurately and non invasively). 5-9 • Disadvantages of MRI: expensive and limited availability. • CT has 47% sensitivity and 74% specificity for the identification of pituitary microadenomas and most commonly reveals a hypodense lesion that usually fails to enhance with contrast administration. 5, 6 • Petrosal sinus sampling may be indicated: 1-5, 11 • In patients with clinically suspected pituitary microadenoma but normal MRI. • To confirm or exclude pituitary origin of ACTH (eg suspected ectopic ACTH).

COMPUTED TOMOGRAPHY (CT) ADRENALS • Most sensitive method for finding adrenal tumour in a patient with ACTH- independent Cushing’s syndrome. 1-4 • As the size of the adrenal mass is the most important feature distinguishing benign adenoma from adrenocortical carcinoma, a CT scan is all that is required in most cases. 12 • May differentiate between adenoma and hyperplasia, but hyperplastic adrenal glands have a variable appearance and CT diagnosis of adrenal hyperplasia is not very reliable: 1-4 1. Nodularity and bilateral gland enlargement suggests hyperplasia. 2. Nodule and contralateral atrophy suggests functioning adenoma. 3. Nodule in otherwise normal gland may be either hyperplasia or functioning adenoma.

ADRENAL SCINITIGRAPHY • Adrenal scintigraphy with radiocholesterol (NP-59) is useful in: 13 1. Differentiating a benign cortical neoplasm (adenoma), which usually takes up iodocholesterol from a malignant cortical neoplasm (carcinoma) which usually does not. 2. Detecting unusual variant of the ACTH-independent Cushing’s syndrome. • Somatostatin receptor scintigraphy can be used to localise ectopic ACTH-secreting tumours. 14 • Disadvantages: exposure to radiation, limited isotope availability and poor imaging of malignant adrenal neoplasms.

88 REFERENCES 1. Goldfarb DA. Contemporary evaluation and management of Cushing’s syndrome. World J Urol 1999; 17: 22-25. (Review) 2. Boscharo M, Barzon L, Fallo F, et al. Cushing’s syndrome. Lancet 2001; 357: 783- 791. 3. Newell-Price J, Jorgensen JOL, Grossman A. The diagnosis and differential diagnosis of cushing’s syndrome. Hormone Research 1999; 51(S3): 81-94. 4. Ross RJM, Trainer PJ. Endocrine investigation: Cushing’s syndrome. Clinical Endocrinology 1998; 49: 153-155. 5. Kaye TB, Crapo L. The cushing syndrome: an update on diagnostic tests. Ann Intern Med 1990; 112: 434-444. (Review of 9 studies – Level II evidence) 6. Buchfelder M, Nistor R, Fahlbusch R, et al. The accuracy of CT and MR evaluation of the sella turcica for detection of adrenocorticotropic hormone-secreting adenomas in Cushing disease. AJNR 1993; 14: 1183-1190. (Retrospective study cohort of 125 CT and 78 MRI – Level III evidence) 7. Peck WW, Dillon WP, Norman D, et al. High resolution MR imaging of pituitary microadenomas at 1.5T: experience with Cushing’s disease. AJR 1989; 152: 145- 151. (Retrospective study cohort of 27 patients – Level III evidence) 8. De Herder WW, Uitterlinden P, Pieterman H, et al. Pituitary tumour localisation in patients with cushing’s disease by magnetic resonance imaging: is there a place for petrosal sinus sampling? Clin Endocrinology (Oxf) 1994; 40: 87-92. 9. Colombo N, Loli P, Vignati F, et al. MR of corticotropic-secreting pituitary microadenomas. AJNR 1994; 15: 1591-1595. (Retrospective study 26 case controls – Level IV evidence) 10. Doppman JL, Frank JA, Dwyer AJ, et al. Gadolinium DTPA enhanced MR imaging of ACTH-secreting microadenomas of the pituitary gland. J Comput Assist Tomogr 1988; 12: 728-735. (Retrospective study 8 patients with cushing’s disease and surgically proven pituitary microadenomas – Level IV evidence) 11. Oldfield EH, Doppman JL, Nieman LK, et al. Petrosal sinus sampling with and without corticotropin-releasing hormone for the differential diagnosis of cushing’s syndrome. NEJM 1991; 325; 897-905. (Prospective study 281 patients – Level III evidence) 12. Daitich JA, Goldfarb DA, Novick AC. Cleveland clinic experience with adrenal cushing’s syndrome. J Urol 1997; 158: 2051-2055. (Retrospective study cohort of 40 patients with cushing’s syndrome – Level III evidence) 13. Fig LM, Gross MD, Shapiro B, et al. Adrenal localisation in the adrenocorticotropic hormone-independent Cushing syndrome. Ann Intern Med 1988; 109: 547-553. (Retrospective study cohort of 24 patients – Level III evidence) 14. De Herder WW, Krenning EP, Mak/Ichoff CD, et al. Somatostatin receptor scintigraphy: its value in tumour localisation in patients with cushing’s syndrome caused by ectopic corticotropin or corticotropin-releasing hormone secretion. Am J Med 1994; 96: 305-312. (Cohort of 10 patients – Level III evidence)

Further Reading 1. Cushing syndrome. Current Probl Surg, July 2001; 489-545.

89 INVESTIGATION OF PHAEOCHROMOCYTOMA

IMAGING IN PHAEOCHROMOCYTOMA • Imaging is used for localisation of phaeochromocytoma in patients with proven biochemical abnormality consistent with phaeochromocytoma and is not for diagnosis. 1 • Localisation of the tumour helps in surgical planning and reduces the chance of negative findings at if the tumour happens to be located outside the abdomen. 2 • “Rule of tens” in locating phaeochromocytomas: 3 • 10% are extra-adrenal. • 10% of phaeochromocytomas are multiple. • 10% are malignant at diagnosis. • 10% are familial and part of MEN syndrome (MEN 2 = Medullary carcinoma of thyroid ± phaeochromocytoma ± primary hyperparathyroidism, etc)

BIOCHEMICAL TESTS • Biochemical diagnosis of phaeochromocytoma must be established prior to the performance of imaging studies to avoid unnecessary surgery because 3% to 7% of patients over the age of 50 have nonfunctioning adrenal nodules (“incidentalomas”). 4 • Total urinary levels of catecholamines and their metabolites over 24 hours have high sensitivity for diagnosing phaeochromocytoma. 5, 6 • Limitations of biochemical tests: 5, 6

90 • False negative results may result from exogenous drugs or episodic catecholamine production. • False positive results with illness, stress, etc.

COMPUTED TOMOGRAPHY (CT) • Initial imaging modality of choice for localisation of phaeochromocytomas. 1, 7 • High sensitivity (>90%) for localisation of abdominal and thoracic phaeochromocytoma when biochemical tests are clearly diagnostic of phaeochromocytoma. 7-9 • Limitations: 7 • Low (~50%) specificity as adrenal “incidentalomas” are common. • Not suitable for whole-body screening. • Can be difficult to interpret when there are anatomical changes or metal clips from surgery. • Cautions: 1 1. Intravenous iodinated contrast media have been reported to precipitate a hypertensive crisis in patients who are not pre-blocked with anti-adrenergic agents. While this is anecdotal, if a phaeochromocytoma is suspected, it is wise to block the patient before administration of contrast agents. 2. CT-guided percutaneous adrenal biopsy on unsuspected phaeochromocytoma has been associated with cardiovascular crises.

META-IODOBENZYLGUANIDINE (MIBG) SCINTIGRAPHY • High sensitivity (85%) and specificity (>95%) for detection and localisation of phaeochromocytomas. 7-12 • Either 123I- MIBG or 131I-MIBG can be used for imaging. However, 123I-MIBG is preferred because of clearer depiction of phaeochromocytoma with 123I-MIBG compared to 131I-MIBG. 3 • Indications: 7, 8, 11, 13 1. To detect extra-adrenal, metastatic, or recurrent sites of disease or when whole- body imaging is important. 2. When CT fails to detect the tumour. 3. To confirm the biochemical activity of CT detected masses and to identify or exclude extra-adrenal phaeochromocytomas. 4. When biochemical tests are inconclusive (MIBG can confirm or exclude the diagnosis). • Limitations of MIBG scan: 1 • Not all phaeochromocytomas concentrate MIBG and drugs such as labetalol, reserpine, calcium channel blockers and some tricyclic antidepressants are known to interfere with the uptake of MIBG. • FDG- Positron emission tomography (PET) is useful in defining the distribution of those phaeochromocytomas that fail to concentrate MIBG. 14 • Magnetic resonance imaging is useful for detecting extraadrenal phaeochromocytomas and recurrence after resection, given increased signal intensity on T2- weighted images. 7-10

91 REFERENCES 1. Sheps SG, Jiang NS, Klee GG. Diagnostic evaluation of phaeochromocytoma. Endocrinology and Metabolic Clin North America 1998; 17: 397-414. (Review) 2. Pattou F, Combermale F, Poirette JF, et al. Questionability of the benefits of routine laparotomy as the surgical approach for phaeochromocytomas and abdominal paragangliomas. Surgery 1996; 120: 1006-1012. (Retrospective study cohort of 100 patients – Level III evidence) 3. Sisson JC, Shulkin BL. Nuclear medicine imaging of phaeochromocytoma and neuroblastoma. Q J Nucl Med 1999; 43: 217-223. (Review) 4. Bornstein SR, Stratakis CA, Chrousos GP. Adrenocortical tumors: recent advances in basic concepts and clinical management. Ann Intern Med 1999; 130: 759-771. 5. Wittles RM, Kaplan EL, Roizen MF. Sensitivity of diagnostic and localization tests for phaeochromocytoma in clinical practice. Arch Intern Med 2000; 160: 2521- 2524. (Retrospective study of 35 case controls – Level IV evidence) 6. Lucon AM, Pereira MA, Mendonca BB, et al. Phaeochromocytoma: study of 50 cases. J Urol 1997; 157: 1208-1212. (Retrospective study 50 patients – Level III evidence) 7. Berglund AS, Hulthen UL, Manhem P, et al. Metaiodobenzylguanidine (MIBG) scintigraphy and computed tomography in clinical practice. Primary and secondary evaluation for localization of phaeochromocytomas. Journal of Internal Medicine 2001; 249(3): 247-51. (Retrospective study cohort of 64 consecutive patients – Level II evidence) 8. Maurea S, Cuocolo A, Reynolds JC, et al. Iodine-131-metaiodobenzylguanidine scintigraphy in preoperative evaluation of paragangliomas: comparison with CT and MRI. J Nucl Med 1993; 34: 173-179. (Prospective cohort of 36 patients – Level III evidence) 9. Jalil ND, Pattou FN, Combemale F, et al. Effectiveness and limitations of pre- operative imaging studies for localisation of phaeochromocytomas: a review of 282 cases. Eur J Surg 1998; 164:23-28. (Retrospective study cohort of 282 cases – Level III evidence) 10. Velchik M, Alavi A, Kressel H, et al. Localization of phaeochromocytoma: MIBG, CT, and MRI correlation. J Nucl Med 1989; 30: 328-336.. (Prospective patients 19 patients – Level III evidence) 11. Shapiro B, Copp JE, Sisson JC, et al. Iodine-131 metaiodobenzylguanidine for the locating of suspected pheochromocytoma: experience in 400 cases. J Nucl Med 1985; 26: 576-585. (Cohort of 400 patients – Level II/III evidence) 12. Van der Harst E, de Herder WW, Bruining HA, et al. 123I metaiodobenzylguanidine and 111-In octreotide uptake in benign and malignant pheochromocytomas. J Clin Endocrinol & Metabolism 2001; 86: 685-693. (Cohort of 70 patients – Level III evidence) 13. Hanson MW, Feldman JM, Beam CA, et al. Iodine 131-labeled metaiodobenzlguanidine scintigraphy and biochemical analyses in suspected phaeochromocytoma. Arch Intern Med 1991; 151: 1397-1402. (Cohort of 64 patients – Level II/III evidence) 14. Shulkin BL, Thompson NW, Shapiro B, et al. Pheochromocytomas: imaging with 2- (fluorine-18) fluro-2-deoxy-D-glucose PET. Radiology 1999; 212: 35-41. (Prospective study 29 patients – Level II/III evidence)

Further Reading 1. Walther MM, Keiser HR, Linehan WM. Pheochromocytoma: evaluation, diagnosis, and treatment. World J Urol 1999; 17: 35-39. (Review)

92 INVESTIGATION OF PRIMARY HYPERALDOSTERONISM

PRIMARY HYPERALDOSTERONISM • The incidence of hyperaldosteronism as a cause for hypertension is believed to be more common than previously thought. 2-10% of patients with hypertension have hyperaldosteronism. 1 • Imaging is used for localisation of a biochemically proven abnormality. 1, 2 • The most important distinction to be made is between the two most common causes of primary hyperaldosteronism: 1, 2 • Aldosterone producing adenoma (APA) and • Bilateral adrenal hyperplasia or Idiopathic hyperaldosteronism (IHA). • Aldosterone producing adenoma is treated surgically and idiopathic hyperaldosteronism /bilateral adrenal hyperplasia is treated medically. 1, 2

BIOCHEMICAL EVALUATION • Plasma aldosterone concentration to plasma renin activity ratio (PAC/PRA) is regarded as the screening test of choice for primary hyperaldosteronism (PA). 1, 3 • Biochemical diagnosis of primary hyperaldosteronism must be established prior to the performance of imaging studies to avoid unnecessary surgery because 3% to 7% of patients over the age of 50 have nonfunctioning adrenal nodules (“incidentalomas”). 4

SPIRAL COMPUTED TOMOGRAPHY OF ADRENALS • Initial imaging modality of choice for localisation of biochemically proven primary hyperaldosteronism. 1, 2 • Only the patients with biochemically confirmed aldosterone excess should undergo CT to detect an adrenal lesion. 5 • 50-60% sensitivity. 6-8

93 • Advantages: non-invasive and is useful in mapping the position of veins prior to adrenal vein sampling. • Limitations: • Unreliable in differentiation between adenoma and hyperplasia. Therefore, adrenal vein sampling should be performed routinely in the investigation of patients with primary hyperaldosteronism. 6, 8-10 • Adrenal gland scintigraphy using iodo-methyl-19-norcholesterol with the dexamethasone suppression can be used to differentiate adenoma from hyperplasia and to determine whether the hyperfunctioning lesions are bilateral. 10, 11

ADRENAL VEIN SAMPLING (AVS) • Most reliable method to localise the abnormal adrenal gland. 6, 8-10, 12 • Close liaison with biochemistry is essential. Renin must be suppressed at the time of the study ie patient must not be taking spironolactone or amiloride. • Most sensitive test to differentiate aldosterone-producing adenoma (APA) from idiopathic hyperaldosteronism (ie. bilateral adrenal hyperplasia/IHA). 8, 9, 12 • The aldosterone to cortisol ratio in both adrenal veins is compared. If one side has a concentration more than 2 times the other side, then APA is diagnosed; otherwise IHA/bilateral adrenal hyperplasia is the diagnosis by default. 12 • When successful, AVS unequivocally establishes the presence or absence of unilateral aldosterone production, thus clarifying the choice of therapy – medical or surgical. 1 • Performed prior to laparoscopic adrenalectomy even if adenoma is shown on CT because of the possibility of co-existent non-functioning adenoma and hyperplasia. 8, 9, 12 • Disadvantages: invasive, highly operator-dependent, not widely available and carries a finite risk of venous thrombosis, adrenal haemorrhage, and adrenal insufficiency.

94 REFERENCES 1. Thakkar RB, Oparil S. Primary aldosteronism: a practical approach to diagnosis and treatment. J Clin Hypertension 2001; 3(3): 189-195. (Review) 2. Ganguly A. Primary aldosteronism. NEJM 1998; 339 (25): 1828-1834. (Review) 3. Soule S, Davidson JS, Rayner BL. The evaluation of primary hyperaldosteronism. SAMJ 2000; 90 (4): 387-394. (Level II/III evidence) 4. Bornstein SR, Stratakis CA, Chrousos GP. Adrenocortical tumors: recent advances in basic concepts and clinical management. Ann Intern Med 1999; 130: 759-771. 5. Radin DR, Manoogian C, Nadler JL. Diagnosis of primary hyperaldosteronism: importance of correlating CT findings with endocrinologic studies. AJR 1992; 158: 553-557. (Retrospective study 20 patients – Level III evidence) 6. Doppman JL, Gill JR Jr, Miller DL, et al. Distinction between hyperaldosteronism due to bilateral hyperplasia and unilateral aldosteronoma: reliability of CT. Radiology 1992; 184: 677-682. (Retrospective study cohort of 24 patients – Level II evidence) 7. Dunnick NR, Leight GS, Robidoux MA, et al. CT in the diagnosis of primary aldosteronism: sensitivity in 29 patients. AJR 1993; 160: 321-324. (Retrospective study cohort of 29 patients – Level III evidence) 8. Harper R, Ferrett CG, McKnight JA, et al. Accuracy of CT and adrenal vein sampling in the pre-operative sampling localization of aldosterone-secreting adrenal adenomas. Q J Med 1999; 92: 643-650. (Retrospective cohort study 34 patients – Level III evidence) 9. Magill SB, Raff H, Shaker JL, et al. Comparison of adrenal vein sampling and computed tomography in the differentiation of primary aldosteronism. J Clin Endocrinol & Metabolism 2001; 86: 1066-1071. (Retrospective study 38 patients – Level III evidence) 10. Ikeda DM, Francis IR, Glazer Gm, et al. The detection of adrenal tumors and hyperplasia in patients with primary aldosteronism: comparison of scintigraphy, CT and MR imaging. AJR 1989; 153: 301-306. (Cohort of 17 patients – Level III evidence) 11. Nocaudie-Calzada M, Huglo D, Lambert M, et al. Efficacy of iodine-131 6-beta- methyl-iodo-19-norcholesterol scintigraphy and computed tomography in patients with primary aldosteronism. Eur J Nucl Med 1999; 26: 1326-1332. (Retrospective study cohort of 41 patients – Level III evidence) 12. Young WF Jr, Stanson AW, Grant CS, et al. Primary aldosteronism: adrenal venous sampling. Surgery 1996; 120: 913-919. (Prospective study 34 patients – Level II/III evidence)

95 INVESTIGATION OF SUSPECTED PRIMARY HYPERPARATHYROIDISM

PRIMARY HYPERPARATHYROIDISM • Primary hyperparathyroidism is an endocrine disorder resulting from the autonomous functioning of one or more parathyroid glands. 1 • The causes of primary hyperparathyroidism include a single parathyroid adenoma (80-85%), parathyroid hyperplasia (10-15%), multiple adenomas (2-3%), and very rarely, parathyroid adenocarcinoma (<1%). 1 • The role of imaging for preoperative localisation of the parathyroid glands remains controversial. 1 • Traditionally, bilateral neck exploration with direct visualisation and evaluation of all four parathyroid glands has been the primary surgical method for treating primary hyperparathyroidism, with success rates >95% in experienced hands. Therefore, pre-operative localisation studies were not usually necessary. 2 • Increasingly, surgeons prefer pre-operative imaging, especially when considering minimally invasive surgery. 1, 2 • Imaging is usually required when there is recurrent disease as the success rates for repeat bilateral neck exploration after an initial failed surgery may be as low as 60%. In such cases of recurrent or persistent hyperparathyroidism, localisation studies have improved the ability to identify the site of the remaining abnormal parathyroid tissue. 3, 4 • The main advantages of pre-operative imaging are: 1. The potential to reduce the time in surgery. 5, 6 2. The ability to limit surgical exploration to the affected side. 7, 8 3. The detection of ectopic abnormal parathyroid glands. 9 • Technetium TC 99m sestamibi imaging and sonography have been the most widely used imaging techniques for the localisation of parathyroid adenomas. 1 • Invasive procedures such as selective venous sampling and selective angiography are expensive, and technically difficult; and therefore rarely used. 10 • Image-guided biopsy is performed in cases where percutaneous ethanol ablation as a first line therapy is considered or when the results of imaging procedures are equivocal. 11 • Note: it is important to consider and exclude Familial Hypocalciuric Hypercalcaemia (FHH) in mild cases of primary hyperparathyroidism. FHH does

96 not require surgery and is a major cause of “failed” neck exploration in primary hyperparathyroidism.

SESTAMIBI NUCLEAR MEDICINE SCAN • Used for pre-operative localisation of abnormal parathyroid glands in the following cases: 1. Recurrent or persistent hyperparathyroidism. 3, 12 2. Where minimally invasive surgery is intended. 13, 14 3. Difficult cases. 15 • Includes the neck and the mediastinum for detection of ectopic abnormal parathyroid glands. 9 • High sensitivity (50-75%) and specificity (>90%) for the detection of abnormal parathyroid glands. 16-19 • Correlating the functional imaging provided by sestamibi scan with a technique with superior anatomical resolution such as US, CT or MRI improves the sensitivity for detection of abnormal parathyroid tissue. 12, 13, 16, 17 • Limitations: • Relatively poor image resolution and anatomical information (compared to US, CT or MRI). 17 • False negatives can occur in patients with small adenomas and with hyperplasia. 16

ULTRASONOGRAPHY • Used for identification and localisation of parathyroid adenomas in patients with primary hyperparathyroidism who undergo minimally invasive surgery. 7, 8, 13 • Sensitivity ranges from 36% to 78%. 8, 13, 16, 17 • Advantages: 20 • Superior anatomical resolution (provides more detailed information of adenoma characteristics and relationships to other structures in the neck). • Useful in evaluation of thyroid abnormalities. • Relatively inexpensive. • Lack of ionising radiation. • Limitations: 20 • Inability to localise the small percentage (2%) of parathyroid adenomas that lie outside the neck. • Low sensitivity in recurrent or persistent primary hyperparathyroidism.

INTRAOPERATIVE ULTRASOUND • Useful in difficult cases. 11 • May limit the extent of dissection in a previously operated field. 11

97 REFERENCES 1. Loevner LA. Imaging of the parathyroid glands. Semin US, CT and MRI 1996; 17: 563-575. 2. Howe JR. Minimally invasive parathyroid surgery. Surg Clin North Am 2000; 80: 1399-1426. 3. Numerow LM, Morita ET, Clark OH, et al. Persistent/recurrent hyperparathyroidism: a comparison of sestamibi scintigraphy, MRI, and ultrasonography. J Magn Reson Imaging 1995; 5: 702-708. (Retrospective study cohort of 23 patients – Level III evidence) 4. Mitchell BK, Merrell RC, Kinder BK. Localization studies in patients with hyperparathyroidism. Surg Clin North Am 1995; 75: 483-498. 5. Wei JP, Burke GJ. Analysis of savings in operative time for primary hyperparathyroidism using localization with technetium 99m sestamibi scan. Am J Surg 1995; 170: 488-491. (Retrospective study cohort of 33 patients – Level III evidence) 6. Hindie E, Melliere D, Perlemuter L, et al. Primary hyperparathyroidism: higher success rate of first surgery after preoperative Tc-99m sestamibi-I-123 subtraction scanning. Radiology 1997; 204: 221-228. (Prospective study 65 patients – Level II evidence) 7. Smit PC, Rinkes IHMB, van Dalen A, et al. Direct, minimally invasive adenomectomy for primary hyperparathyroidism: an alternative to conventional neck exploration? Annals of Surgery 2000; 231(4): 559-565. (Prospective study 110 consecutive patients – Level II evidence) 8. Van Dalen A, Smit CP, van Vroonhoven TJM, et al. Minimally invasive surgery for solitary parathyroid adenomas in patients with primary hyperparathyroidism: role of US with supplemental CT. Radiology 2001; 220: 631-639. (Prospective study cohort of 94 consecutive patients – Level II evidence) 9. Ishibashi M, Nishida H, Hiromatsu Y, et al. Localization of ectopic parathyroid glands using technetium-99m sestamibi imaging: comparison with magnetic resonance and computed tomographic imaging. Eur J Nucl Med 1997; 24: 197-201. (Prospective study 11 patients – Level III evidence) 10. Miller DL. Endocrine angiography and venous sampling. Radiol Clin North America 1993; 31: 1051-1067. 11. Gritzmann N, Koischwitz D, Rettenbacher T. Sonography of the thyroid and parathyroid glands. Radiologic Clin North America 2000; 38(5): 1131-1145. 12. Gotway MB, Reddy GP, Webb WR, et al. Comparison between MR imaging and 99m-Tc MIBI scintigraphy in the evaluation of recurrent or persistent hyperparathyroidism. Radiology 2001; 218: 783-790. (Retrospective study cohort of 98 consecutive patients – Level II evidence) 13. Purcell GP, Dirbas FM, Jeffrey RB, et al. Parathyroid localization with high- resolution ultrasound and technetium Tc 99m sestamibi. Arch Surg 1999; 134: 824- 830. (Prospective study 61 consecutive patients – Level II evidence) 14. Borley NR, Collins RE, O’Doherty M, et al. Technetium-99m sestamibi parathyroid localization is accurate enough for scan-directed unilateral neck exploration. Br J Surg 1996; 83: 989-991. (Retrospective study cohort of 48 patients – Level II/III evidence) 15. Lee VS, Wilkinson RH Jr, Leight GS, et al. Hyperparathyroidism in high-risk surgical patients: evaluation with double-phase technetium 99m sestamibi imaging. Radiology 1995; 197: 627-633. (cohort of 39 patients – Level III evidence) 16. Krubsack AJ, Wilson SD, Lawson TL, et al. Prospective comparison of radionuclide, computed tomographic, sonographic, and magnetic resonance

98 localization of parathyroid tumours. Surgery 1989; 106: 639-646. (Prospective blinded study 100 patients – Level II evidence) 17. De Feo ML, Colagrande S, Biagini C, et al. Parathyroid glands: combination of 99mTc MIBI scintigraphy and US for demonstration of parathyroid glands and nodules. Radiology 2000; 214: 393-402. (Retrospective study 49 patients + prospective single blind study of 16 patients – Level II/III evidence) 18. Ishibashi M, Nishida H, Hiromatsu Y, et al. Comparison of technetium-99m MIBI, technetium-99m-tetrofosmin, ultrasound and MRI for localization of abnormal parathyroid glands. J Nucl Med 1998; 39: 320-324. (Cohort of 20 patients – Level III evidence) 19. Shaha AR, Sarkar S, Strashun A, et al. Sestamibi scan for preoperative localization in primary hyperparathyroidism. Head & Neck 1997; 19: 87-91. (Retrospective study cohort of 24 patients – Level III evidence) 20. Reeder SB, Desser TS, Weigel RJ, et al. Sonography in primary hyperparathyroidism: review with emphasis in scanning technique. J Ultrasound Med 2002; 21: 539-552.

Further Reading 1. Gotway MB, Leung JWT, Gooding GA, et al. Hyperfunctioning parathyroid tissue: spectrum of appearances on non-invasive imaging. AJR 2002; 179: 495-502.

99 CLINICALLY PALPABLE SOLITARY THYROID NODULE

CLINICALLY PALPABLE SOLITARY THYROID NODULE • Questions for imaging: 1 1. Is the lesion truly solitary or part of a multinodular process (5% of solitary nodules are malignant; <1% malignant if part of multinodular goitre) 2. If solitary, is it malignant?

NUCLEAR MEDICINE SCAN • Role of nuclear scintigraphy in the evaluation of thyroid nodules includes: 1 1. To determine the functional status of a nodule in a patient with biochemical or clinical evidence of hyperthyroidism. 2. To detect ectopic thyroid tissue. 3. Useful in the post-operative management of patients with thyroid cancer.

100 • The two most commonly used isotopes are radioiodine (I-123) and technetium pertechnetate (99m-Tc). I-123 is the isotope of choice for functional evaluation and 99m-Tc for anatomical evaluation. 1 • Limitations: 1 • Ingestion of certain drugs or iodine containing preparations may greatly impair uptake of the tracer and degrade the image quality. • Not useful in the setting of hypothyroidism as the tracer requires the presence of functioning follicular cells for uptake.

ULTRASOUND (US) • Routine use of US is not indicated in the evaluation of clinically palpable thyroid lesion. 1-3 • US is useful in the following situations: 2, 3 1. To confirm the presence of a thyroid mass. 2. To determine whether it is a solitary nodule. 3. To assess any cystic component. 4. To guide fine needle aspiration biopsy. • Advantages: 4 • High sensitivity for detection of small nodules. • Provides superior anatomical detail. • Enables visualisation of the entire anterior neck, determination of size and evaluation of possible other nodules and lymphadenopathy, and characterisation of flow and vascularisation. • Useful adjunct to physical examination when neck palpation is difficult in patients with short fat necks. • Limitations: low specificity (unreliable in distinguishing benign from malignant nodules). 4

FINE NEEDLE ASPIRATION CYTOLOGY (FNAC) • Most accurate diagnostic tool for assessing potentially malignant thyroid lesions/nodules (95% diagnostic accuracy). 5, 6 • High sensitivity (83%) and specificity 92% for diagnosis of thyroid cancer. 7 • Improved accuracy with ultrasound guidance. 8 • Diagnosis of thyroid nodules according to cytological features can be subdivided into the following classifications: 9 1. Malignant (or suspicious of malignancy) 2. Benign 3. Indeterminate (or suspicious of follicular or Hurthle cell neoplasm) 4. Insufficient for diagnosis. • Advantages: 7 • Rapid, relatively inexpensive and safe. • Limitations: 7, 8, 10 • Indeterminate lesions. • Non-diagnostic or unsatisfactory aspirates. • Potential complications.

101 REFERENCES 1. Cases JA, Surks MI. The changing role of scintigraphy in the evaluation of thyroid nodules. Sem Nucl Med 2000; 30(2): 81-87. 2. Naik KS, Bury RF. Imaging the thyroid. Clinical Radiology 1998; 53: 630-638. 3. Marqusee E, Benson CB, Frates MC, et al. Usefulness of ultrasonography in the management of nodular thyroid disease. Ann Intern Med 2000; 133: 696-700. (Retrospective study cohort of 223 patients – Level II evidence) 4. Hegedus L. Thyroid ultrasound. Endocrinology and Metabolism Clinics of North America 2001; 30(2): 339-360. 5. Kountakis SE, Skoulas IG, Maillard AAJ. The radiologic work-up in thyroid surgery: fine-needle biopsy versus scintigraphy and ultrasound. Ear, Nose & Throat Journal 2002; 81(3): 151-154. (Retrospective study 441 patients – Level III/IV evidence) 6. Chiu WY, Chia NH, Wan SK, et al. The investigation and management of thyroid nodules – a retrospective review of 183 cases. Ann Acad Med Singapore 1998; 27: 196-199. (Retrospective study 183 patients – Level III/IV evidence) 7. Gharib H, Goellner JR. Fine needle aspiration biopsy of the thyroid: an appraisal. Ann Intern Med 1993; 118: 282-289. (Literature review – Level II/III evidence) 8. Danese D, Sciacchitano S, Farsetti A, et al. Diagnostic accuracy of conventional versus sonography-guided fine-needle aspiration biopsy of thyroid nodules. Thyroid 1998; 8(1):15-21. (Cohort of 9683 consecutive patients – Level II evidence) 9. Singer PA. Evaluation and management of the solitary thyroid nodule. Otolaryngologic Clin North Am 1996; 29(4): 577-591. 10. Nguyen GK, Ginsberg J, Crockford PM. Fine-needle aspiration biopsy cytology of the thyroid: its value and limitations in the diagnosis and management of solitary thyroid nodules. Pathol Annu 1991; 26:63-91.

Further Reading 1. Gritzmann N, Koischwitz D, Rettenbacher T. Sonography of the thyroid and parathyroid glands. Radiologic Clinics of North America 2000; 38(5): 1131-11455. 2. Feld S, Garcia M, Baskin HJ, et al. AACE clinical practice guidelines for the diagnosis and management of thyroid nodules. Endocr Pract 1996; 2: 78-84. 3. Meier DA, Kaplan MM. Radioiodine uptake and thyroid scintiscanning. Endocrinology & Metabolism Clinics of North America 2001; 30(2): 291-312.

102 THYROID IMAGING AND INCIDENTAL NON-PALPABLE THYROID NODULE

THYROID IMAGING • The most commonly used methods for imaging the thyroid are ultrasound and nuclear medicine scanning with Tc-99m pertechnetate. 1 • In hyperthyroidism, nuclear medicine scans are used to help provide a specific diagnosis and exclude a thyroiditis. 1 • In hypothyroidism and stable multinodular goitre, imaging is rarely indicated. 1 • Patterns of uptake on nuclear medicine scan: 1 1. Generalised increased uptake - Grave’s disease; Hashimoto’s thyroiditis (early) 2. Generalised diminished uptake – Subacute thyroiditis; Hashimoto’s (late); exogenous iodine (IV iodinated contrast agents and some drugs eg. amiodorone should not be administered for at least 6 weeks prior to the test) 3. Focal increased uptake with absent/decreased uptake elsewhere (hot nodule) - functioning adenoma; toxic multinodular goitre 4. Focal diminished uptake (cold nodule) - multinodular goitre; solitary nodule.

INCIDENTAL NON-PALPABLE THYROID NODULE • Nonpalpable thyroid nodules are increasingly recognised during imaging of the head and neck, such as for parathyroid evaluation, carotid disease, or other nonthyroidal disease of the neck. 2 • About 40% of asymptomatic individuals have a nodule on thyroid US. Thyroid cancer is comparatively very rare. 2 • The work up of such a patient depends on whether the clinical suspicion of malignancy is high (prior head and neck irradiation, age younger than 20 or older than 60 years, male sex, family history of medullary thyroid carcinoma, rapid growth, hoarseness, firmness or fixation of the thyroid nodule on palpation, regional lymphadenopathy, or vocal cord paralysis) or low. 3 • If there is no clinical suspicion and nodule is less than 1.0-1.5cm and has no ultrasonographic characteristics suggestive of malignancy, observation is generally recommended with either clinical follow-up palpation or repeat ultrasonography. 2-4 • If carcinoma is suspected or the nodule is at least >1.0cm, Fine needle aspiration biopsy guided by ultrasonography is recommended. 2, 4

103 REFERENCES 1. Naik KS, Bury RF. Imaging the thyroid. Clinical Radiology 1998; 53: 630-638. 2. Tan GH, Gharib H. Thyroid incidentalomas: management approaches to nonpalpable nodules discovered incidentally on thyroid imaging. Ann Intern Med 1997; 126:226-231. (Literature Review – Level II/III evidence) 3. Cases JA, Surks MI. The changing role of scintigraphy in the evaluation of thyroid nodules. Sem Nucl Med 2000; 30(2): 81-87. 4. Papini E, Guglielmi R, Bianchini A, et al. Risk of malignancy in nonpalpable thyroid nodules: predictive value of ultrasound and color Doppler features. J Clin Endocrinol & Metabolism 2002; 87(5): 1941-1946. (Prospective study 402 consecutive patients – Level II evidence)

104 ACUTE BLOODY DIARRHOEA IN ADULTS

ACUTE BLOODY DIARRHOEA IN ADULTS • The commonest causes include: 1. Infective causes 2. Inflammatory non-infective (entero) colitis 3. Ischaemic bowel disease • Infective causes are sought by microbiological examination of the stool. • Acute ischaemic bowel disease when present is usually suspected clinically.

ABDOMINAL RADIOGRAPHY • Most useful in establishing the diagnosis of toxic megacolon, intestinal infarction, and bowel obstruction or perforation. 1-3 • May detect “thumbprinting” in inflammatory and ischaemic colitis and the pattern of faecal residue may suggest the extent of active inflammatory bowel disease. 4

105 • If there is evidence of impending toxic dilatation, then frequent clinical and radiographic monitoring is required. • Further imaging is rarely required in patients with infective disease, but in patients with non-infective inflammatory disease, such as ulcerative colitis or Crohn’s disease, without toxic dilatation, further investigation with flexible +/- instant barium enema, may be required during the acute phase. 1,2

COLONOSCOPY +/- BIOPSY • “Gold standard” for characterising the activity and extent of inflammatory bowel disease. 5, 6 • More sensitive than barium studies in detecting early, subtle changes of inflammatory bowel disease. 7 • with biopsy is superior to barium enema alone, in assessment of the extent of inflammatory bowel disease. 6,7 • In the non-acute phase following a presentation with acute bloody diarrhoea, full investigation with colonoscopy or double-contrast barium enema is indicated +/- small bowel barium studies. • Deferred initially because of an increased risk in the presence of acute severe colitis, toxic megacolon, suspected perforation, or peritonitis. 5 • Advantages: 5 • Allows direct visualisation of intestinal mucosa. • Opportunity to obtain biopsy specimens, allowing histopathological correlation. • Disadvantages: Less accurate at localising strictures and other lesions compared to barium enema. 7

BARIUM ENEMA IN NON-ACUTE PHASE • Double contrast enema is useful for: 2 1. Confirming the diagnosis of inflammatory bowel disease. 2. Assessing the extent and severity of disease. 3. Differentiating ulcerative colitis from Crohn’s disease and other colitides. 4. Following the course of disease. 5. Detecting complications. 6. Evaluating some cases of suspected ischaemic colitis. 8 • Superior to in: 7 • The assessment of colonic distensibility, strictures, and the presence of fistulas. • The estimation of depth of ulceration. • In acute phase, an “instant” barium enema can be performed where endoscopy is unavailable. “Instant” barium enema is a modified technique in which the colon is examined without bowel preparation and barium is run in to the splenic flexure or until faecal residue is encountered. This technique is more useful in ulcerative colitis and has been largely replaced by endoscopy. 2 • Limitations: 2 • Contra-indicated in established or impending toxic megacolon (because of inherent risk of perforation with intraperitoneal leakage of barium). • Presence of barium in the colon may interfere with subsequent colonoscopy and the ability to obtain stool samples for culture. • Lack of direct visualisation of mucosa. • Caution: Overdistension during barium enema in acute colitis should be avoided.

106 SMALL BOWEL STUDIES • Procedure of choice to evaluate the degree, extent, and activity of small bowel involvement in inflammatory bowel disease. 1

RADIONUCLIDE-LABELLED WHITE CELL SCAN • May be used to: 9,10 1. Confirm the diagnosis of inflammatory bowel disease. 11 2. Assess the severity and localise the extent of inflammatory or ischaemic bowel disease in patients with fulminant colitis, in whom barium enema and colonoscopy may be contraindicated. 12-14 3. Confirm relapse. 4. Identify complications such as extramural abscess. • Advantages: 9 • Can guide management differentiating active inflammatory strictures from fibrous strictures. • Can assist in differential diagnosis of Crohn’s disease from ulcerative colitis. • Limitations: 9 • Significant rate of false positives and negatives. • Lack of anatomical detail.

COMPUTED TOMOGRAPHY • May be useful in ischaemic bowel. In addition to showing evidence of bowel ischaemia, the cause may be seen - arterial or venous occlusion. 15 • Useful in advanced Crohn’s disease or when extraintestinal complications are suspected clinically. 2,16 • Advantages: 2,4 • Noninvasive. • Allows evaluation of the bowel wall, its mesentery, peritoneal surfaces, and adjacent organs. • Helps guide percutaneous aspiration/drainage of intra-abdominal abscesses. • Limitations: • Inferior to colonoscopy and double contrast enema in depiction of intestinal mucosa. • Inability to diagnose inflammatory bowel disease in its earliest stages. Therefore, CT plays limited role in the initial evaluation of patients suspected of inflammatory bowel disease.

ANGIOGRAPHY • Shows occlusive cause in minority of cases. Therefore, angiography is usually not indicated in the evaluation of colonic ischaemia. 17 • May be useful in selected group of patients, for example, in those with recurrent ischaemia where it may show stenosis, which may be amendable to angioplasty. 17

107 REFERENCES 1. Scotiniotis I, Rubesin SE, Ginsberg GG. Imaging modalities in inflammatory bowel disease. Gastroenterol Clin N America 1999; 28(2): 391-421. (Review) 2. Gore RM, Ghahremani GG. Radiologic investigation of acute inflammatory and infectious bowel disease. Gastroenterol Clin N America 1995; 24(2): 353-384. (Review) 3. McCook TA, Ravin CE, Rice RP. Abdominal radiographs in the emergency department: a prospective analysis. Ann Emerg Med 1982; 11: 7. 4. Caroline DF, Friedman AC. The radiology of inflammatory bowel disease. Med Clin N America 1994; 78(6): 1353-1385. 5. Quinn PG, Binion DG, Connors PJ. The role of endoscopy in inflammatory bowel disease. Med Clin North America 1994; 78: 1331-1352. 6. Holdstock G, DuBoulay CE, Smith CL. Survey of the use of colonoscopy in inflammatory bowel disease. Dig Dis Sci 1984; 29: 731-734. 7. Dijkstra J, Reeders JWAJ, Tygat GNJ. Idiopathic inflammatory bowel disease: endoscopic-radiologic correlation. Radiology 1995; 197: 369-375. (Prospective blinded study 99 patients – Level II evidence) 8. Iida M, Matsui T, Fuchigami T, et al. Ischemic colitis: serial changes in double contrast barium enema. Radiology 1986; 159: 337-341. (Cohort of 40 patients – Level III evidence) 9. Giaffer MH. Labelled leucocyte scintigraphy in inflammatory bowel disease: clinical applications. Gut 1996; 38: 1-5. 10. Seabold J, Brown M, Datz F, et al. Procedure guideline for Tc-99m exametazime (HMPAO) labeled leukocyte scintigraphy for suspected infection/inflammation. Society of Nuclear Medicine 1999 feb.22p. 11. Kennan N, Hayward M. Tc HMPAO-labeled white cell scintigraphy in Crohn’s disease of the small bowel. Clin Radiol 1992; 45(5): 331-334. (Retrospective study 18 patients – Level III/IV evidence) 12. Weldon MJ. Assessment of inflammatory bowel disease activity using 99m-Tc- HMPAO single photon emission computerized tomography imaging. Scand J Gastroenterol 1994; 203: 61-68. 13. Spinelli F, Milella M, Sara R, et al. The 99mTc-HMPAO leukocyte scan: an alternative to radiology and endoscopy in evaluating the extent and the activity of inflammatory bowel disease. J Nucl Biol Med 1991: 35(2): 82-87. (Cohort of 78 patients – Level III evidence) 14. Allan RA, Sladen GE, Bassingham S, et al. Comparison of simultaneous Tc-99m HMPAO and In-111 oxine labelled white cell scans in the assessment of inflammatory bowel disease. Eur J Nucl Med 1993; 20: 195-200. (Cohort of 47 patients – Level III evidence) 15. Balthazar EJ, Yen BC, Gordon RB. Ischemic colitis: CT evaluation of 54 cases. Radiology 1999; 211-381-388. (Retrospective study 54 case controls – Level IV evidence) 16. Gore RM, Balthazar EJ, Ghahremani GC, et al. CT features of ulcerative colitis and Crohn’s disease. AJR 1996; 167: 3-15. 17. Toursarkissian B, Thompson RW. Ischemic colitis. Surg Clin North America 1997; 77: 461-470.

Further Reading 1. Wills JS, Lobis IF, Denstman FJ. Crohn Disease: state of the art. Radiology 1997; 202: 597-610. (Review)

108 ACUTE GASTROINTESTINAL BLEEDING

ACUTE GASTROINTESTINAL BLEEDING • Acute red blood loss per usually arises from lower GI tract. Commonest causes of colonic acute bleeding are angiodysplasia and diverticulitis.

109 • Patients with acute upper GI bleeding usually present with haematemesis and/or malaena. • Small bowel haemorrhage may present with malaena or red blood per rectum.

ENDOSCOPY • Primary diagnostic modality to evaluate, localise and treat acutely bleeding lesions in suspected upper GI bleed. 1

PROCTOSIGMOIDOSCOPY • In acute lower GI bleeding, proctosigmoidoscopy is performed initially to exclude anorectal causes, such as haemorrhoids. 2

COLONOSCOPY • Colonoscopy may be diagnostic but is often difficult in acute setting. Delayed colonoscopy after stabilisation and oral bowel preparation is usually indicated. However, accelerated bowel preparation and subacute colonscopy within 12-24 hours is often being done nowadays. • Patients with rapid blood loss from upper GI lesions may present with red blood per rectum; passage of nasogastric tube or upper GI endoscopy will exclude this. • Barium study is not indicated for acute GI bleed as it is less sensitive than endoscopy, lacks therapeutic capability, and precludes angiography as a result of retained barium.

RADIONUCLIDE STUDIES • Used to localise mild to moderate or intermittent bleeding, arising below the ligament of Treitz and hence direct selective surgical intervention. 3-6 • Reported accuracy in localising site of GI bleeding varies between 40-90%. 3-7 • Shows GI bleeding as local tracer extravasation into bowel lumen. • 99m-Tc-labelled red blood cells can detect bleeding rates as slow as 0.1ml/min and can be used for prolonged detection of bleeding up to about 24 hours after administration. 8,9 • Advantages: easy to perform, requires no patient preparation and non-invasive. • Inaccurate results may occur unless there is strict adherence to technical detailed criteria for image interpretation. • In younger patients, a Meckel’s scan may be indicated. Meckel’s scan is the study of choice for identifying ectopic gastric mucosa in a Meckel’s diverticulum as the source of unexplained GI bleeding. 10

ANGIOGRAPHY • Diagnostic indications: 1 1. First line localising study or following radionuclide study in the lower GI tract; 2. In upper GI tract, when the diagnosis remains in doubt and patient continues to bleed or bleeding recurs. • Therapeutic indications: 1 1. Continued bleeding after therapeutic endoscopy. 11 2. Active bleeding demonstrated during angiography as contrast extravasation. • Can detect bleeding rates faster than 0.5 - 1.0ml/min. • Sensitivity ranges between 40-92% for lower GI bleed. 12-15 • Increased accuracy for detecting a bleeding source if there is active bleeding.

110 • Some radiologists prefer angiography to be preceded by radionuclide studies in haemodynamically stable patients, to help localise the approximate bleeding site prior to angiography and hence increase the yield of angiography. 16,17 • Therapeutic angiography (intra-arterial vasoconstrictors or embolisation) can represent a definitive treatment or a temporary measure to allow for elective, rather than emergent surgery. • Limitations: • Relative contraindications: severe coagulopathy, congestive cardiac failure, recent myocardial infarct, renal insufficiency, and pregnancy. • 2-4% complication rate. 12,18

TRANSJUGULAR INTRAHEPATIC PORTOSYSTEMIC SHUNT STENT (TIPS) • Radiological procedure of choice for bleeding oesophageal varices unable to be controlled by endoscopic therapy, in Child’s C and most Child’s B patients. 19,20 • Complications of TIPS include hepatic encephalopathy and pulmonary oedema. 19 • Procedural complications include intraperitoneal haemorrhage, neck haematoma, capsule perforation, hepatic artery injury or fistula, biliary-stent fistula, renal failure, portal vein thrombosis. 19

111 REFERENCES 1. Lefkovitz Z, Cappell MS, Kaplan M, et al. Radiology in the diagnosis and therapy of gastrointestinal bleeding. Gastroenterology Clinics of North America 2000; 29(2): 489-512. 2. Zuccaro G Jr. Management of the adult patient with acute lower gastrointestinal bleeding. Am J Gastroenterology 1998; 93: 1202-1208. 3. Suzman MS, Talmor M, Jennis R, et al. Accurate localization and surgical management of active lower gastrointestinal hemorrhage with technetium-labeled erythrocyte scintigraphy. Ann Surg 1996; 224:29-36. (Retrospective study- Level III evidence) 4. Gutierrez C, Mariano M, Vander Laan T, et al. The use of technetium-labeled erythrocyte scintigraphy in the evaluation and treatment of lower gastrointestinal hemorrhage. American Surgeon 1998; 64: 989-992. (Retrospective study- Level III evidence) 5. O’Neill BB, Gosnell JE, Lull RJ, et al. Cinematic nuclear scintigraphy reliably directs surgical intervention for patients with gastrointestinal bleeding. Arch Surg 2000; 135: 1076-1082. (Retrospective study with historical controls- Level III evidence) 6. Emslie JT, Zarnegar K, Siegel ME, et al. Technetium-99m-labeled red blood cell scans in the investigation of gastrointestinal bleeding. Dis Colon Rectum 1996; 39: 750-754. (Retrospective study 80 consecutive patients – Level III evidence) 7. Hunter JM, Pezim ME. Limited value of technetium 99m-labeled red cell scintigraphy in localization of lower gastrointestinal bleeding. Am J Surg 1990; 159: 504-506. (Cohort of 203 patients – Level III evidence) 8. Alavi A, Ring EJ. Localization of gastrointestinal bleeding: superiority of 99m-Tc sulfur colloid compared with angiography. AJR 1981; 137: 741-748. (Cohort of 43 patients – Level III evidence) 9. Bentley DE, Richardson JD. The role of tagged red blood cell imaging in the localization of gastrointestinal bleeding. Arch Surg 1991; 126: 821-824. (Retrospective study 162 patients – Level III evidence) 10. Sfakianakis GN, Conway JJ. Detection of ectopic gastric mucosa in meckel’s diverticulum and in other aberrations by scintigraphy: I. Pathophysiology and 10- year clinical experience. J Nucl Med 1981; 22: 647. 11. Defreyne L, Vanlangenhove P, De Vos M, et al. Embolization as a first approach with endoscopically unmanageable acute nonvariceal gastrointestinal hemorrhage. Radiology 2001; 218: 739-748. (Retrospective study – Level III evidence) 12. Colacchio TA, Forde KA, Patsos TJ, et al. Impact of modern diagnostic methods on the management of active rectal bleeding: Ten year experience. Am J Surg 1982; 143: 607-610. (Retrospective study 178 patients – Level III evidence) 13. Leitman IM, Paull DE, Shires GT III. Evaluation and management of massive lower gastrointestinal hemorrhage. Ann Surg 1989; 209: 175-180. (Cohort of 68 patients – Level III evidence) 14. Whitaker SC, Gregson RHS. The role of angiography in the investigation of acute or chronic gastrointestinal haemorrhage. Clin Radiology 1993; 47: 382-388. (Retrospective study 46 patients – Level III evidence) 15. Zuckerman DA, Bocchini TP, Birnbaum EH. Massive hemorrhage in the lower in adults: diagnostic imaging and intervention. AJR 1993; 161: 703-711. 16. Gunderman R, Leef J, Ong K, et al. Scintigraphic screening prior to visceral arteriography in acute lower gastrointestinal bleeding. J Nucl Med 1998; 39(6): 1081-1083. (Retrospective study- level III evidence)

112 17. Ng DA, Opelka FG, Beck DE, et al. Predictive value of technetium Tc-99m-labeled red blood cell scintigraphy for positive angiogram in massive lower gastrointestinal haemorrhage. Dis Colon Rectum 1997; 40(4): 471-477. (Retrospective study cohort of 160 patients - Level III evidence) 18. Sigstedt B, Lunderquist A. Complications of angiographic examinations. AJR 1978; 130: 455-460. (Prospective study 1217 consecutive patients – Level II evidence) 19. Rosch J, Keller FS. Transjugular intrahepatic portosystemic shunt: present status, comparison with endoscopic therapy and shunt surgery, and future prospectives. World J Surg 2001; 25: 337-346. (Review) 20. Jalan R, Lui HF, Redhead DN, et al. TIPSS 10 years on. Gut 2000; 46: 581-584. (Review)

113 ACUTE LEFT ILIAC FOSSA / PELVIC PAIN

114 Common causes of acute left iliac fossa pain include: • Acute sigmoid diverticulitis • Tubo-ovarian pathology and ectopic pregnancy in females • Ischaemic colitis • Pseudomembranous colitis • Inflammatory bowel disease • Locally perforated sigmoid carcinoma • Renal colic • Leaking abdominal aortic aneurysm

PLAIN RADIOGRAPHY • Erect Chest radiograph (CXR) is useful in excluding pneumoperitoneum and in assessment of coincidental cardiorespiratory pathology. 1,2 • Abdominal radiographs (AXR) may show non-specific findings such as pneumoperitoneum, ileus, complete or partial bowel obstruction or a soft tissue mass. 1,2

COMPUTED TOMOGRAPHY • Imaging modality of choice for evaluation of suspected acute diverticulitis, especially in older patients. 3,4 • Superior to other imaging modalities for: • Confirming the diagnosis of diverticulitis (>90% sensitivity). 5-8 • Defining the extent and severity of pericolic process. 5-8 • Establishing the presence of complications such abscess, fistula formation and bowel obstruction. 5-8 • Providing information directing appropriate management. 5 • Indications for CT include: 1 • When patient is seriously ill. • When clinical diagnosis is in doubt. • Clinical deterioration. • Exclusion of pericolic abscess. • CT criteria of diverticulitis include: 3,4 • Presence of diverticula with pericolic infiltration of fatty tissue. • Thickening of colonic wall. • Abscess formation. • Advantages: 3,4 • Allows examination of the colonic wall, pericolonic and extracolonic disease. • Provides alternative diagnoses for patients in whom diverticulitis has been excluded. 7,8 • Helps guide percutaneous aspiration/drainage of diverticular abscess. 9,10 • Limitations: • A negative CT scan does not completely exclude the diagnosis of acute diverticulitis. 5-8 • Features of colon cancer may overlap with those of diverticulitis and it may not be possible to differentiate acute diverticulitis from a perforated cancer in the acute phase of the illness. Therefore, follow-up delayed imaging is indicated with colonoscopy or barium enema to distinguish these pathologies. 11

115 PELVIC ULTRASOUND AND TRANSVAGINAL ULTRASOUND • First imaging examination of choice for evaluation of acute pelvic pain in young females in the reproductive age group. 3,12 • Provides information regarding the uterus, adnexa and ovaries in young women with left lower quadrant/pelvic pain. 3,12 • Transvaginal ultrasound where available and appropriate can provide more detailed examination for gynaecological disease. 12 • 85% sensitivity for diagnosing acute diverticulitis. 13-15 • Characteristic findings in acute diverticulitis include: 3 • Hypoechoic bowel wall thickening. • Presence of diverticula or abscesses. • Hyperechogenicity surrounding the bowel wall, implying active inflammation. • Advantages: rapid, non-invasive, inexpensive, no ionising radiation, and requires no patient preparation or contrast material administration. • Limitations: 3 • Interloop abscesses and abscesses filled with gas may not be well visualised or may mimic loops of bowel. • Limited value in diagnosing bowel-related pathology. • If there is suspicion of acute diverticulitis or diverticular abscess on US, CT may be indicated for further delineation.

DOUBLE CONTRAST BARIUM ENEMA (DCBE) • Usually not performed in the acute situation, as it is associated with risk of perforation and is inferior to CT in showing extramural pathology. 6 • Water soluble contrast enema can be performed for diagnostic purposes as an alternative if CT is not available. • In the acute phase, demonstration of extravasated contrast material outlining an abscess cavity, sinus tract of fistula is diagnostic of diverticulitis. 1 • An extraluminal mass compressing or displacing the bowel is the most common finding in severe diverticulitis but is non-specific for the diagnosis. 2 • A delayed DCBE or colonoscopy 4-6 weeks after acute episode is performed: • To assess the extent of disease. • To assess residual stricturing. • To exclude perforated carcinoma and other colonic pathology. • Limitations: • Inability to directly demonstrate extramucosal process. 6 • Invasive.

COLONOSCOPY • Generally avoided in initial evaluation because of risk of perforation. • Can help exclude other diagnoses, such as inflammatory bowel disease, carcinoma, or ischaemic colitis, when the diagnosis of diverticulitis is unclear.

116 REFERENCES 1. Stollman NH, Raskin JB, et al. Practice guidelines: Diagnosis and management of diverticular disease of the colon in adults. Am J Gastroenterology 1999; 94(11): 3110-3121. 2. McKee RF Deignan RW, Krukowski ZH. Radiological investigation in acute diverticulitis. Br J Surg 1993; 80: 560-565. (Review) 3. O’Malley ME, Wilson SR. Ultrasonography and computed tomography of appendicitis and diverticulitis. Seminars in Roentgenology 2001; 36(2): 138-147. (Review) 4. Rao PM. CT of diverticulitis and alternative conditions. Seminars in US, CT, and MRI 1999; 20(2): 86-93. (Review) 5. Ambrosetti P, Grossholz M, Becker C, et al. Computed tomography in acute left colonic diverticulitis. Br J surg 1997; 84: 532-534. (Prospective study cohort of 423 patients – Level II/III evidence) 6. Cho KC, Morehouse HT, Alterman DD, et al. Sigmoid diverticulitis: diagnostic role of CT- comparison with barium enema studies. Radiology 1990; 176: 111-115. (Prospective study 56 patients – Level II/III evidence) 7. Rao PM, Rhea JT, Novelline RA, et al. Helical CT with only colonic contrast material for diagnosing diverticulitis: prospective evaluation of 150 patients. AJR 1998; 170: 1445-1449. (Prospective study 150 consecutive patients – Level II evidence) 8. Eggesbo HB, Jacobsen T, Kolmannskog F, et al. Diagnosis of acute left sided colonic diverticulitis by three radiological modalities. Acta Radiologica 1998; 39: 315-321. (Prospective study 32 consecutive patients – Level II/III evidence) 9. Neff CC, vanSonnenberg E, Casola G, et al. Diverticular abscesses: percutaneous drainage. Radiology 1987; 163: 15-18. (Cohort of 16 patients – Level III evidence) 10. Stabile Be, Puccio E, van Sonnenberg E, et al. Preoperative percutaneous drainage of diverticular abscesses. Am J Surg 1990; 159: 99-105. (Cohort of 19 patients – Level III evidence) 11. Chintapalli KN, Chopra S, Ghiatas AA, et al. Diverticulitis versus colonic cancer: differentiation with helical CT findings. Radiology 1999; 210: 429-435. (large blinded study – Level II evidence) 12. Bau A, Atri M. Acute female pelvic pain: Ultrasound evaluation. Seminars in US, CT, and MRI 2000; 21: 78-93. (Review) 13. Zielke A, Hasse C, Nies C, et al. Prospective evaluation of ultrasonography in acute colonic diverticulitis. Br J Surg 1997; 84: 385-388. (Prospective study 187 consecutive patients – Level II evidence) 14. Pradel JA, Adell JF, Taourel P, et al. Acute colonic diverticulitis: prospective evaluation with US and CT. Radiology 1997; 205: 503-512. (Prospective study 64 consecutive patients – Level II evidence) 15. Verbanck J, Lambrecht S, Rutgeerts L, et al. Can sonography diagnose acute colonic diverticulitis in patients with acute intestinal inflammation? A prospective study. J Clin Ultrasound 1989; 17: 661-666. (Prospective study 123 patients – Level II evidence)

Further Reading 1. Helical CT in the evaluation of the acute abdomen. AJR 2000; 174: 901-913. 2. Urban BA, Fishman EK. Targeted helical CT of the acute abdomen: appendicitis, diverticulitis, and small bowel obstruction. Seminars in US, CT and MRI 2000; 21: 20-39. 3. Ferzoco LB, Raptopoulos V, Silen W. Acute diverticulitis. NEJM 1998; 338(21): 1521-1526.

117 ACUTE PANCREATITIS

ACUTE PANCREATITIS • The diagnosis of pancreatitis is usually made clinically and biochemically. 1 • In suspected acute pancreatitis, imaging is used to: 1 1. Exclude an underlying cause (eg gallstones) 2. Assess severity 3. Detect complications.

PLAIN RADIOGRAPHS • Chest and abdominal radiographs are usually performed to exclude other pathology such as perforated viscus and intestinal obstruction. 1 • May show a spectrum of non-specific changes depending on the disease severity eg generalised or local ileus (sentinel loop), a colon cut off and a renal halo sign. 2

118 ULTRASOUND (US) • Recommended initially in all patients with suspected acute pancreatitis. 1,3 • Primarily used to assess the biliary tree for gallstones, duct dilatation/obstruction, and to exclude other pathology. 1,3 • Helps distinguish fluid collections from solid inflammatory masses. • Useful for follow-up of pancreatic fluid collections. 4 • Limitations: • Visualisation of the is usually sub-optimal due to overlying bowel gas from a coexistent ileus. 5,6 • Detection of intraparenchymal and retroperitoneal fluid collections correlates poorly with pancreatic necrosis. 3

COMPUTED TOMOGRAPHY (CT) • Contrast enhanced CT is the imaging modality of choice for evaluating the pancreas and the surroundings. 3,7 • Routine CT is not indicated in mild acute pancreatitis unless there are clinical or other signs of deterioration. 1,7,8 • 14-28% CT scans are normal in mild pancreatitis. 7,8 • Indications for CT scan include: 1,3,8 1. Diagnostic uncertainty 2. Assessment of severe cases 3. Failure to improve on treatment 4. Clinical findings suggesting a developing complication (eg, fever, pain, hypotension, decreasing haematocrit) 5. Sudden deterioration in clinical status following an initial response to medical treatment 6. Follow-up and monitoring of established complications 7. Guidance of interventional procedures such as percutaneous fine needle aspiration and/or catheter drainage of fluid collections. • Combination of pre and post-contrast enhancement appearances permits the assessment of the degree of pancreatic necrosis and surrounding peri-pancreatic and intra-abdominal fluid collections (assessment of severity of the disease). 9 • Disadvantages: substantial exposure to ionising radiation with repeat scanning.

ENDOSCOPIC RETROGRADE CHOLANGIOPANCREATOGRAPHY (ERCP) • Mainly used to locate and remove gallstones in the common among patients with severe pancreatitis attributable to gallstones. 1 • Urgent ERCP and sphincterotomy is indicated in patients with severe gallstone pancreatitis who fail to respond to treatment within 48 hours. 10,11 • Similarly patients with gallstone acute pancreatitis who develop ascending cholangitis stand to benefit from early ERCP and endoscopic sphincterotomy. 12

FLUID COLLECTIONS IN ACUTE PANCREATITIS • The question of intervention (usually percutaneous aspiration/ drainage) for relatively symptomatic pseudocysts/fluid collections is a balance between, on the one hand, the risks of introducing infection into a sterile collection and draining an “immature” cyst, and on the other hand waiting too long since complications of a large untreated, unresolved fluid collection increases with time. 13-15 • Indications for aspiration/drainage include:

119 1. Diagnosis of possible infection/abscess. If aspiration confirms infection, possible therapeutic regimens are dependent on the morphology of the collection and the clinical status of the patient, and include: • Percutaneous catheter drainage either as a definitive procedure or as a “holding” measure pending surgery. • Surgical drainage/debridement as a first-line treatment. • Endoscopic drainage via the or duodenum. 2. Continuing symptoms considered due to the mass effect of the fluid collection. 3. Cyst enlarging on serial follow-up imaging. In this situation, ERCP may be useful. If communication between the pancreatic duct and the fluid collection is demonstrated, the need for prolonged drainage is likely and surgery may be a better option. 4. Some authorities suggest size alone as a criterion for drainage (usually around 5 cm). • 30-50% of acute fluid collections resolve spontaneously without the need for intervention. 16

120 REFERENCES 1. United kingdom guidelines for the management of acute pancreatitis. Gut 1998; 42(suppl 2): S1-S13. 2. Rifkind KM, Lawerence LR, Ranson JHC. Initial roentgenographic sign in acute pancreatitis: a study of findings in 73 patients. N Y State J Med 1976; 76: 1968. 3. Balthazar EJ. Acute pancreatitis: assessment of severity with clinical and CT evaluation. Radiology 2002; 223: 603-613. 4. Dalzell DP, Scharling ES, Ott DJ, et al. Acute pancreatitis: The role of diagnostic imaging. Crit Rev Diagn Imaging 1998; 39(5): 339-363. 5. Silverstein W, Isikoff M, Hill M, et al. Diagnostic imaging of acute pancreatitis: prospective study using CT and sonography. AJR 1981; 137: 497-502. (Level III evidence) 6. McKay A, Imrie C, O’Neill J, et al. Is an early ultrasound scan of value in acute pancreatitis? Br J Surg 1982; 69: 369-372. (Level III evidence) 7. Jacobs JE, Birnbaum BA. Computed tomography evaluation of acute pancreatitis. Seminars in Roentgenology 2001; 36(2): 92-98. 8. Balthazar EJ, Freeny PC, vanSonnenberg E, et al. Imaging and intervention in acute pancreatitis. Radiology 1994; 193: 297-306. 9. Balthazar EJ, Robinson DL, Megibow AJ, et al. Acute pancreatitis: value of CT in establishing prognosis. Radiology 1990; 174: 331-336. (Cohort of 88 patients - Level II/III evidence) 10. Neoptolemos JP, Carr-Locke DL, London NJ, et al. Controlled trial of urgent retrograde cholangiopancreatography and endoscopic sphincterotomy versus conservative treatment for acute pancreatitis due to gallstones. Lancet 1988; 2:979- 983. (Randomised controlled trial - Level I/II evidence) 11. Fan ST, Lai ECS, Mok FPT, et al. Early treatment of acute biliary pancreatitis by endoscopic papillotomy. NEJM 1993: 328: 228-232. (Randomised controlled study 195 patients – Level I/II evidence) 12. Neoptolemos J, Carr-Locke D, Leese T, et al. Acute cholangitis in association with acute pancreatitis: incidence, clinical features and outcome in relation to ERCP and endoscopic sphincterotomy. B J Surg 1987; 74: 1103-1106. (Level III evidence) 13. Mithofer K, Mueller PK, Warshaw Al. Interventional and surgical treatment of pancreatic abscess. World J Surg 1997; 21: 162. 14. VanSonnenberg E, Wittich GR, Casola G, et al. Percutaneous drainage of infected and non infected pancreatic pseudocysts: experience in 101 cases. Radiology 1989; 170: 757. (Level III evidence) 15. VanSonnenberg E, Wittich GR, Chon KS, et al. Percutaneous radiologic drainage of pancreatic abscesses. AJR 1997; 168: 979. (Retrospective study 59 patients – Level III evidence) 16. Balthazar EJ. Complications of acute pancreatitis: clinical and CT evaluation. Radiol Clin N Am 2002; 40: 1211-1227.

Further Reading 1. Piironen A. Severe acute pancreatitis: contrast-enhanced CT and MRI features. Abdom Imaging 2001; 26: 225-233. 2. Steinberg W, Tenner S. Acute pancreatitis. NEJM 1994; 330: 1198-1210.

121 ACUTE RIGHT ILIAC FOSSA / PELVIC PAIN

122 Common Causes • Acute appendicitis (most common cause) • Tubo-ovarian pathology and ectopic pregnancy in females • Mesenteric adenitis • Right sided diverticulitis • Inflammatory bowel disease • Epiploic appendagitis • Omental torsion/infarction • Renal colic

Tubo-ovarian pathology includes: • Pelvic inflammatory disease (salpingitis, tubo-ovarian abscess) • Ovarian cyst accident (ruptured ovarian cyst, haemorrhage, ovarian or fallopian tube torsion) • Endometriosis • Ectopic pregnancy

ACUTE APPENDICITIS • Usually a clinical diagnosis and routine imaging is not indicated. 1-4 • Some advocate the routine use of imaging to reduce the negative appendicectomy rates. 5,6 • Imaging is useful in clinically equivocal cases or in differentiation from gynaecological diseases. 1-4 • Both CT and US have high sensitivity and specificity in diagnosing acute appendicitis and the choice between the two modalities is dependent on institution preference and on available expertise, although patient age, sex, and body habitus are important influencing factors. Ultrasound has major advantage of lack of exposure to ionising radiation. 1-4

GRADED COMPRESSION ULTRASONOGRAPHY • First choice in thin patients, children, young women and pregnant women. 1,4 • 90-95% diagnostic accuracy for acute appendicitis. 6-10 • An inflamed appendix usually measures greater than 6mm in diameter, is noncompressible and tender with focal compression. 9,10 • Provides information regarding the uterus, adnexa and ovaries in young women with right lower quadrant/pelvic pain. 1,4 • Advantages: rapid, noninvasive, inexpensive, no ionising radiation, and requires no patient preparation or contrast material administration. • Disadvantages: lower sensitivity and specificity for perforated appendicitis, difficult examination in retrocaecal appendicitis and obese patients. 11,12

TRANSVAGINAL ULTRASONOGRAPHY (TVUS) • Where available and appropriate can provide more detailed examination for gynaecological disease. 13 • TVUS and b-HCG have high accuracy for the diagnosis of ectopic pregnancy. 14 • Ultrasonographic findings suggestive of an ectopic pregnancy include: 15 • Fluid in the Pouch of Douglas, an adnexal mass and an empty uterus • An adnexal mass, empty uterus or pseudogestational sac and a positive b-HCG.

COMPUTED TOMOGRAPHY (CT) • 94-98% diagnostic accuracy for acute appendicitis (superior to US). 5,7,16,17 123 • Superior to US in staging periappendiceal inflammation and abscesses, providing alternative diagnoses and in revealing the normal appendix. 7, 17 • CT signs of appendicitis include an abnormal appendix, periappendiceal inflammation, and caecal apical changes. 7 • Recommended whenever US results are suboptimal, indeterminate, or normal in patients with acute abdominal pain. 1-3 • Can be used as a first choice in obese patients who would be difficult to image with US, and in patients who are suspected of having appendiceal perforation. • Imaging modality of choice in some centres, especially in United States of America. 1 • Disadvantages: ionising radiation, expensive and requires the use of contrast material

OTHER IMAGING • If US is normal or indeterminate, further imaging depends on the provisional diagnosis. 1 • In females, may be required to exclude tubo-ovarian pathology or ectopic pregnancy. • CT is useful if there is suspicion of diverticulitis, or bowel related abscess. • Barium studies or colonoscopy are performed in inflammatory bowel disease. • IVP or non-enhanced spiral CT may be indicated in renal colic.

124 REFERENCES 1. O’Malley ME, Wilson SR. Ultrasonography and computed tomography of appendicitis and diverticulitis. Seminars in Roentgenology 2001; 36(2): 138-147. (Review) 2. Birnbaum BA, Wilson SR. Appendicitis at the Millennium. Radiology 2000; 215: 337-348. (Review) 3. Rao PM, Boland GWL. Imaging of acute right lower abdominal quadrant pain. Clinical Radiology 1998; 53: 639-649. (Review) 4. Birnbaum BS, Jeffery RB Jr. CT and sonographic evaluation of acute right lower quadrant pain. AJR 1998; 170: 361-371. (Review) 5. Rao PM, Rhea JT, Novelline RA, et al. Effect of computed tomography of the appendix on treatment of patients and use of hospital resources. NEJM 1998; 338(3): 141-146. (Prospective study 100 consecutive patients – Level II evidence) 6. Chen SC, Chen KM, Wang SM, et al. Abdominal ultrasonography screening of clinically diagnosed or suspected appendicitis before surgery. World J Surg 1998; 22: 449-452. (Prospective study 191 patients – Level II evidence) 7. Balthazar EJ, Birnbaum BA, Yee J, et al. Acute appendicitis: CT and US correlation in 100 patients. Radiology 1994; 190: 31-35. (Prospective study 100 consecutive patients - Level II evidence) 8. Jeffrey RB, Laing FC, Lewis FR. Acute appendicitis: high-resolution real-time US findings. Radiology 1987; 163: 11-14. (Cohort of 90 patients – Level III evidence) 9. Jeffrey RB, Laing FC, Townsend RR. Acute appendicitis: sonographic criteria based on 250 cases. Radiology 1988; 167: 327-329. (Cohort of 250 consecutive patients – Level II evidence) 10. Puylaert JB. Acute appendicitis: US evaluation using graded compression. Radiology 1986; 158: 355-360. (Cohort of 60 consecutive patients – Level II evidence) 11. Puylaert JBCM, Rutgers PH, Lalisang RI, et al. A prospective study of ultrasonography in the diagnosis of appendicitis. NEJM 1987; 317: 666-669. (Prospective study 111 consecutive patients – Level II evidence) 12. Borushok KF, Jeffrey RB Jr, Laing FC, et al. Sonographic diagnosis of perforation in patients with acute appendicitis. AJR 1990; 154: 275-278. (Retrospective study cohort of 100 patients with acute appendicitis – Level III evidence) 13. Jain KA, Hamper UM, Sanders RC. Comparison of transvaginal and transabdominal sonography in the detection of early pregnancy and its complications. AJR 1988; 151: 1139-1143. (Cohort of 90 consecutive pregnant women – Level II/III evidence) 14. Braffman Bh, Coleman BG, Ramachandani P, et al. Emergency department screening for ectopic pregnancy: A prospective US study. Radiology 1994; 190: 797-802. (Prospective study 1427 consecutive patients – Level II evidence) 15. Bau A, Atri M. Acute female pelvic pain: Ultrasound evaluation. Seminars in US, CT, and MRI 2000; 21: 78-93. (Review) 16. Rao PM, Rhea JT, Novelline RA, et al. Helical CT technique for the diagnosis of appendicitis: prospective evaluation of focused appendix CT examination. Radiology 1997; 202: 139-144. (Prospective study 100 consecutive patients – Level II evidence) 17. Wise SW, Labuski MR, Kasales CJ, et al. Comparative assessment of CT and sonographic techniques for appendiceal imaging. AJR 2001; 176: 933-941. (Prospective study 100 consecutive patients – Level II evidence)

125 ACUTE RIGHT UPPER QUADRANT PAIN/ACUTE CHOLECYSTITIS

Acute cholecystitis is a common cause of acute right upper quadrant pain but other conditions such as peptic ulcer disease and pancreatitis can mimic acute cholecystitis.

PLAIN RADIOGRAPHS • Abdominal radiographs are usually not indicated, as most gallstones are not radio- opaque. • Chest radiographs may be performed to exclude a thoracic cause of pain and bowel perforation. 1

126 ULTRASONOGRAPHY • Initial investigation of choice for suspected acute cholecystitis. 2-4 • Ultrasonographic signs of acute inflammation include gallbladder wall thickening/oedema, pericholecystic fluid, gallstones, and positive ultrasonic 4,5 murphy’s sign. • >90% diagnostic accuracy and varies with the morphologic criteria used. 4,6-8 • Colour/power Doppler increases accuracy over Gray-scale sonography. 6 • Advantages: allows evaluation of other abdominal structures (can identify an alternative diagnosis), provides preoperative information such as gallbladder size, stone size, gallbladder wall status, and the presence of biliary dilatation. 9

Tc- IDA RADIONUCLIDE SCAN • Superior diagnostic accuracy and specificity compared to ultrasound. 7,8 • Used to clarify a negative, equivocal or technically difficult ultrasound in the presence of continued clinical suspicion of acute cholecystitis. 9 • The hallmark of acute cholecystitis (acalculous as well as calculous) is persistent gall bladder non-visualisation 30 minutes post morphine or on the 3-4 hour delayed image. 9 • False positives can occur in alcoholics, intensive care unit patients, patients on prolonged fasting, cystic fibrosis and chronic cholecystitis. 10 • Morphine augmentation reduces false positives and is superior to delayed imaging. 11-13 • In critically ill patients in whom acalculous cholecystitis is suggested on US, Tc- IDA scan with pretreatment Cholecystokinin to empty gallbladder prior to Tc-IDA scan, or percutaneous may be indicated. • Post treatment Cholecystokinin can be used to evaluate gallbladder function in chronic cholecystitis. 14,15 • Limitations: longer examination time, unreliable in severe hepatocellular disease or at serum bilirubin levels >340-500 mmol/L, and inability to diagnose extra-biliary causes of acute right upper quadrant abdominal pain and to provide anatomical information. 9

OTHER IMAGING • Barium studies, endoscopy or CT scan may be indicated in certain patients, to identify alternative diagnoses such as peptic ulcer disease, pancreatitis, gastroenteritis and bowel obstruction, which may clinically simulate acute cholecystitis. • CT may be indicated to evaluate complications of acute cholecystitis.

127 REFERENCES 1. Field S, Guy PJ, Upsdell SM, et al. The erect abdominal radiograph in the acute abdomen: should its routine use be abandoned? BMJ 1985; 290: 1934-1936. (Prospective study 102 consecutive patients – Level II evidence) 2. Laing FC, Federle MP, Jeffery RB, et al. Ultrasonic evaluation of patients with acute right upper quadrant pain. Radiology 1981; 140: 449-455. (Prospective study 52 patients- Level III evidence) 3. Harvey RT, Miller WT. Acute biliary disease: Initial CT and follow-up US versus Initial US and follow-up CT. Radiology 1999; 213: 831-836. (Retrospective study cohort of 123 patients - Level III evidence) 4. Ralls DW, Colletti PM, Lapin SA, et al. Real time sonography in suspected acute cholecystitis. Prospective evaluation of primary and secondary signs. Radiology 1985; 155:767-771. (Prospective study 497 consecutive patients - Level II evidence) 5. Yarmentitis SD. Ultrasound of the gallbladder and the biliary tree. European Radiology 2002; 12: 270-282. (Review) 6. Soyer P, Brouland JP, Boudaif M, et al. Colour velocity imaging and power doppler sonography of the gallbladder wall: a new look at the sonographic diagnosis of acute cholecystitis. AJR 1998; 171: 183-188. (Prospective study 129 consecutive patients – Level II/III evidence) 7. Chatsiioannou SN, Moore WH, Ford PV, et al. Hepatobiliary scintigraphy is superior to abdominal ultrasonography in suspected acute cholecystitis. Surgery 2000; 127: 609-13. (Retrospective study cohort of 107 consecutive patients – Level II evidence) 8. Shea JA, Berlin JA, Escarce JJ, et al. Revised estimates of diagnostic test sensitivity and specificity in suspected biliary tract disease. Arch Intern Med 1994; 154: 2573- 2581.(Meta-analysis 27 studies – Level II/III evidence) 9. Lin EC, Kuni CC. Radionuclide imaging of hepatic and biliary disease. Seminars in liver disease 2001; 21(2): 179-194. (Review) 10. Fig LM, Wahl RL, Stewart RE, et al. Morphine-augmented hepatobiliary scintigraphy in the severely ill: caution is in order. Radiology 1990; 175: 467-473. (Retrospective study cohort of 51 studies – Level III evidence) 11. Flancbaum L, Choban PS, Sinha R, et al. Morphine in the evaluation of hospitalized patients with suspected acute cholecystitis. Annals of Surgery 1994; 220: 25-31. (Retrospective study cohort of 163 patients - Level III evidence) 12. Kim CK, Tse KKM, Juweid M, et al. Cholescintigraphy in the diagnosis of acute cholecystitis: morphine augmentation is superior to delayed imaging. J Nucl Med 1993; 34: 1866-1870. ( Cohort of 306 consecutive patients – Level II evidence) 13. Flancbaum L, Choban PS. Use of morphine cholescintigraphy in the diagnosis of acute cholecystitis in the critically ill patients. Intensive Care Med 1995; 21: 120- 124. (Retrospective study cohort of 45 patients - Level III evidence). 14. Yap L, Wycherley AG, Morphett AD, et al. Acalculous biliary pain: cholecystectomy alleviates symptoms in patients with abnormal cholescintigraphy. Gastroenterology 1991; 101: 786-793. (Prospective randomised study 103 patients – Level II/III evidence) 15. Fink-Bennett D, DeRidder P, Kolozsi WZ, et al. Cholecystokinin cholescintigraphy: detection of abnormal gall bladder function in patients with chronic acalculous gallbladder disease. J Nucl Med 1991; 32: 1695-1699. (Retrospective study cohort of 374 patients – Level III evidence)

128 BLUNT ABDOMINAL TRAUMA

COMPUTED TOMOGRAPHY • Imaging modality of choice in the initial evaluation of haemodynamically stable blunt trauma injury. 1-5 • Most accurate (>95% sensitivity and specificity) and cost effective modality for localisation and grading of specific organ injuries which helps decide if a patient needs a period of close observation or urgent therapeutic intervention. 6-8 129 • Initial CT of the abdomen should be performed with intravenous contrast to facilitate the diagnosis of hollow viscus injuries. 1 • Use of oral contrast is controversial. A multicenter trial is underway in Australia to evaluate the use of oral contrast in CT in blunt abdominal trauma patients. • Direct signs of free intraperitoneal or retroperitoneal perforation as well as signs of a vascular mesenteric lesion usually mandate , whereas other, more indirect signs may raise the suspicion of a bowel injury and warrant further investigation or close observation. 9 • High negative predictive value of spiral CT and repeat standardised abdominal examination can help decide which patients can be safely discharged home. 5-10 • Plays an important role in the detection and management of renal injuries. 9 • Advantages: 11 • Gives complete visualisation of the intra-abdominal solid organs. • Sensitive for the detection of intra-abdominal or retroperitoneal haematoma and pneumoperitoneum, which may result from a bowel injury. • Limitations: 11 • Not appropriate for haemodynamically unstable patients. • Less sensitive in detection of bowel injury. 12

FOCUSED ABDOMINAL SONOGRAPHY IN TRAUMA (FAST) • Imaging modality of choice for initial screening for free abdominal fluid and parenchymal injuries in haemodynamically unstable patients. 11,13-15 • Enables selection of haemodynamically unstable patients with significant haemoperitoneum for immediate exploratory laparotomy. 13-15 • Sensitivity of 80-90% and specificity of 96-98% for detection of intra-abdominal injuries from blunt trauma (relies on the presence of intraperitoneal fluid). 6,11,16 • Recent Level III studies support the routine use of abdominal US in the evaluation of patients with blunt abdominal trauma. However, large well-designed prospective trials need to be conducted to support this. 11,14-19 • Advantages: 11 • Rapid, non-invasive. • No patient preparation. • No exposure to ionising radiation. • Does not interfere with . • Allows serial imaging to reassess the patient should there be interval change in the patient’s haemodynamics or condition. • Limitations: 4,11,16 • If an intra-abdominal injury does not result in haemoperitoneum or visible organ injury, it may be missed on an initial scan because most scanning techniques rely on the detection of intra-abdominal fluid to guide further evaluation. 16,20 • Inability to fully evaluate the retroperitoneum (kidneys, duodenum, and pancreas). • Inability to detect bowel injury or active bleeding. • Does not accurately predict the need for surgery in splenic injuries.

CYSTOGRAPHY • Immediate is indicated in blunt trauma patients when there is evidence of gross haematuria with pelvic fracture (to detect bladder rupture). 21,22 • Relative indications for cystography include gross haematuria without pelvic fracture, and microhaematuria with pelvic fracture. 21

130 • CT cystography has comparable accuracy to that of conventional radiographic cystography provided adequate retrograde bladder distension is achieved with at least 300ml dilute contrast. 23

ANGIOGRAPHY • Usually indicated in suspected vascular trauma or ongoing blood loss from renal, splenic or pelvic injuries provided that surgery is not indicated in unstable patients. 24 • Angiographic embolization is an adjunct in the non-operative management of the haemodynamically stable patient with hepatic and splenic injuries and evidence of ongoing bleeding. 25,26

131 REFERENCES 1. EAST Practice Management Guidelines Work Group. Practice management guidelines for the nonoperative management of blunt injury to the liver and spleen. EAST practice management guidelines for trauma 2000. 2. Hughes TM. The diagnosis of gastrointestinal tract injuries resulting from blunt trauma. Aust N Z J Surg 1999; 69: 770-777. (Review) 3. Becker CD, Mentha G. Blunt abdominal trauma in adults: role of CT in the diagnosis and management of visceral injuries. Part I: Liver and Spleen. Eur Radiology 1998; 8: 553-562. 4. Shuman WP. CT of blunt abdominal trauma in adults. Radiology 1997; 205(2): 297- 306. 5. Brasel KJ, Borgstrom DC, Kolewe KA, et al. Abdominal computed tomography scan as a screening tool in blunt abdominal trauma. Surgery 1996; 120: 780-784. (Retrospective study 238 patients – Level II/III evidence) 6. Liu M, Lee CH, P’eng FK. Prospective comparison of diagnostic peritoneal lavage, computed tomographic scanning, and ultrasonography for the diagnosis of blunt abdominal trauma. J Trauma 1993; 35(2): 267-270. (Prospective study 55 patients – Level II evidence) 7. Navarrete-Navarro P, Vazquez G, Bosch JM, et al. Computer tomography vs clinical and multidisciplinary procedures for evaluation of severe abdomen and chest trauma - a cost analysis approach. Intensive Care Med 1996; 22: 208-212. (Randomised trial 103 patients with severe blunt trauma – Level I/II evidence) 8. Federle MP, Courcoulas AP, Powell M, et al. Blunt splenic injury in adults: clinical and CT criteria for management with emphasis on active extravasation. Radiology 1998; 206: 137-142. (Retrospective blinded study 270 patients – Level II evidence) 9. Becker CD, Mentha G, Schmidlin F, et al. Blunt abdominal trauma in adults: role of CT in the diagnosis and management of visceral injuries. Part II: Gastrointestinal tract and retroperitoneal organs. Eur Radiology 1998; 8: 772-780. 10. Livingston DH, Lavery RF, Passannante MR, et al. Admission or observation is not necessary after a negative abdominal computed tomography scan in patients with suspected blunt abdominal trauma: results of a prospective, multi-institutional trial. J Trauma 1998; 44: 273-282. (Prospective multi-institutional study 2822 consecutive patients – Level II evidence) 11. Amoroso TA. Evaluation of the patient with blunt abdominal trauma: an evidence based approach. Emergency Medicine Clinics of North America. 1999; 17(1): 63- 75. 12. Butela ST, Federle MP, Chang PJ, et al. Performance of CT in detection of bowel injury. AJR 2001; 176: 129-135. (Retrospective study 112 patients – Level III evidence) 13. Poletti P-A, Wintermark M, Schnyder P, et al. Traumatic injuries: role of imaging in the management of the victim (conservative expectation). Eur Radiology 2002; 12: 969-978. 14. Bode PJ, Edwards MJR, Kruit MC, et al. Sonography in a clinical algorithm for early evaluation of 1671 patients with blunt abdominal trauma. AJR 1999; 172: 905- 911. (Prospective study 1671 consecutive patients – Level II evidence) 15. McGahan JP, Richards JR. Blunt abdominal trauma: the role of emergent sonography and a review of the literature. AJR 1999; 172: 897-903. 16. Brown MA, Casola G, Sirlin C, et al. Blunt abdominal trauma: screening US in 2,693 patients. Radiology 2001; 218: 352-358. (Retrospective study 2699 patients – Level II/III evidence) 17. Rose JS, Levitt MA, Porter J, et al. Does the presence of ultrasound really affect computed tomographic scan use? A prospective randomized trial of ultrasound in

132 trauma. J Trauma 2001; 51: 545-550. (Prospective randomised trial 288 patients – Level II evidence) 18. Brown CK, Dunn KA, Wilson K. Diagnostic evaluation of patients with blunt abdominal trauma: a decision analysis. Academic Emergency Medicine 2000; 7(4): 385-396. (Decision analysis – Level II/III evidence) 19. Branney SW, Moore EE, Cantrill SV, et al. Ultrasound based key clinical pathway reduces the use of hospital resources for the evaluation of blunt abdominal trauma. J Trauma. Surgery 1996; 120: 780. (Prospective case control study with historical controls – Level II/III evidence) 20. Chiu WC, Cushing BM, Rodiriguez A, et al. Abdominal injuries without haemoperitoneum: a potential limitation of focused abdominal sonography for trauma (FAST). J Trauma 1997; 42: 617. (Level III evidence) 21. Morgan DE, Nallamala LK, Kenney PJ, et al. CT cystography: radiographic and clinical predictors of bladder rupture. AJR 2000; 174: 89-95. (Prospective study 157 consecutive patients – Level II/III evidence) 22. Morey AF, Iverson AJ, Swan A, et al. Bladder rupture after blunt trauma: guidelines for diagnostic imaging. J Trauma 2001: 51: 683-686. (Retrospective study 53 patients– Level III evidence) 23. Peng MY, Parisky YR, Cornwell EE, et al. CT cystography versus conventional cystography in evaluation of bladder injury. AJR 1999; 173: 1269-1272. (Prospective study 55 consecutive patients– Level II evidence) 24. Hagiwara A, Sakaki S, Goto H, et al. The role of in the management of blunt renal injury: a practical protocol. J Trauma 2001; 51: 526-531. (Prospective study 46 patients – Level II /III evidence) 25. Hagiwara A, Yukioka T, Satou M, et al. Nonsurgical management of patients with blunt hepatic injury: efficacy of transcatheter arterial embolization. AJR 1997; 169: 1151-1156. (Prospective study 31 patients – Level II/III evidence) 26. Hagiwara A, Yukioka T, Ohta S, et al. Nonsurgical management of patients with blunt splenic injury: efficacy of transcatheter arterial embolization. AJR 1996; 167: 159-166. (Prospective study 54 patients – Level II/III evidence)

133 CHRONIC PANCREATITIS

ULTRASOUND • Imaging modality of choice for imaging of the biliary tract. 1 • May reveal pancreatic enlargement, ductal dilatation, or pseudocysts, with a sensitivity of 60-70% and specificity of 80-90%. 2,3 • Useful for follow-up of fluid collections. 3

COMPUTED TOMOGRAPHY • Sensitivity of 74-90% and specificity of 85% in the diagnosis of chronic pancreatitis. 4 • Superior to US in detection of calcifications and cystic areas. 4 • CT features of chronic pancreatitis include pancreatic ductal dilatation, parenchymal atrophy, and pancreatic calculi. 4 • Useful for exclusion of malignancy or mass.

ENDOSCOPIC ULTRASOUND (EUS) • Preliminary results of EUS in the evaluation of early chronic pancreatitis have been promising, but its specific diagnostic role is under investigation. 5,6 • Detects changes of mild chronic pancreatitis that may not be detectable from other imaging modalities, but can be confirmed by histology. 6-9 • Advantages: less invasive than ERCP with fewer complications. 5 • Disadvantages: 5 • Inability to perform some therapeutic applications such as sphincterotomy and stent placement in the pancreatic duct. • High inter-observer variability. • Requires sedation and endoscopy. • Limited availability. MAGNETIC RESONANCE PANCREATOGRAPHY (MRCP) • Non invasive alternative to diagnostic ERCP, with comparable accuracy. 10,11 • Useful in identifying pancreatic duct anomalies eg pancreas divisum. 12

134 • Visualisation of the pancreatic duct can be improved by secretin stimulation and can be used to detect minor papillary stenosis in pancreas divisum. 12 • Advantages: non-invasive outpatient procedure, easily performed, and involves no use of contrast agent or radiation. • Limitations: • Does not offer therapeutic opportunity. • Limited availability. • High expense.

ENDOSCOPIC RETROGRADE CHOLANGIOPANCREATOGRAPHY • “Gold standard” imaging procedure for diagnosing chronic pancreatitis and planning treatment. 13 • Main indications for ERCP in chronic pancreatitis are: 14 1. To assist the diagnosis. 2. To evaluate the status of the pancreatic and biliary ducts. 3. To detect anatomical variations such as pancreatic divisum. 4. To define the relation between a fluid collection and the pancreatic duct prior to percutaneous or surgical drainage. • Advantages: provides therapeutic opportunity. • Disadvantages: 15 • Requires direct cannulation of the common bile or pancreatic duct. • ~ 4% complication rate (pancreatitis, haemorrhage, sepsis, bile leakage and 6 mortality). • Unsuccessful cannulation of the ducts in 3-9%.

135 REFERENCES 1. Weltman DI, Zeman RK. Acute diseases of the gallbladder and bile ducts. Radiol Clin North Am 1994; 32: 933-950. 2. Bastid C, Sahel J, Filho M, et al. Diameter of the main pancreatic duct in chronic calcifying pancreatitis. Mesurement by ultrasonography versus pancreatography. Pancreas 1990; 5: 424-527. (Prospective study 60 patients– Level III evidence) 3. Niederau C, Grendell JH. Diagnosis of chronic pancreatitis. Gastroenterology 1985; 88: 1973-1995. 4. Luetmer PH, Stephens DH, Ward EM, et al. Chronic Pancreatitis: Reassessment with current CT. Radiology 1989; 171: 353-357. (Retrospective study 56 consecutive patients – Level III/IV evidence) 5. Wallace MB, Hawes RH. in the evaluation and treatment of chronic pancreatitis. Pancreas 2001; 23: 26-35. 6. Catalano MF, Lahoti S, Geenen JE, et al. Prospective evaluation of endoscopic ultrasonography and endoscopic retrograde pancreatography and secretin test in the diagnosis of chronic pancreatitis. Gastrointest Endosc 1998; 48: 11-17. (Level II/III evidence) 7. Nattermann C, Goldschmidt AJ, Dancygier H. Endosonography in chronic pancreatitis – a comparison between endoscopic retrograde pancreatography and endoscopic ultrasonography. Endoscopy 1993; 25: 565-570. (Level II/III evidence) 8. Wierema MJ, Hawes RH, Lehman GA, et al. Prospective evaluation of endoscopic ultrasonography and endoscopic retrograde cholangiopancreatography in patients with chronic abdominal pain of suspected pancreatic origin. Endoscopy 1993; 25: 555-564. (Level II/III evidence) 9. Zimmerman MJ, Mishra G, Lewin DN, et al. Comparison of EUS findings with histopathology in chronic pancreatitis (abstract). Gastrointest Endosc 1997; 45: AB185. 10. Sica GT, Braver J, Cooney MJ, et al. Comparison of endoscopic cholangiopancreatography with cholangiopancreatography in patients with pancreatitis. Radiology 1999; 210: 605-610. (Retrospective study 39 patients- Level III/IV evidence) 11. Takehara Y, Ichijo K, Tooyama N, Kodaira N, et al. Breath hold MR cholangio- panceatography with a long-echo-train fast spin-echo sequence and a surface coil in chronic pancreatitis. Radiology 1994; 192: 73-78. (Prospective study 39 patients – Level III evidence) 12. Fukukura Y, Fujiyoshi F, Sasaki M, et al. Pancreatic duct: morphologic evaluation with MR cholangiopancreatography after secretin stimulation. Radiology 2002; 222: 674-680. (Prospective study 203 patients – Level II evidence) 13. Steer ML, Waxman I, Freedman S. Chronic pancreatitis. NEJM 1995; 332: 1482- 1490. 14. Axon ATR. Endoscopic retrograde in chronic pancreatitis: Cambridge classification. Radiol Clin North Am 1989; 27: 39-50. 15. Bilbao MK, Dutter CT, Lee TG, et al. Complications of retrograde cholangio- pancreatography (ERCP): a study of 10,000 cases. Gastroenterology 1976; 70: 314- 320. (Level II evidence)

136 DYSPEPSIA

137 “Dyspepsia is a symptom complex of epigastric pain or discomfort thought to originate in the upper gastrointestinal tract, and it may include any of the following symptoms: heartburn, acid regurgitation, excessive burping/belching, increased abdominal bloating, nausea, feeling of abnormal or slow digestion, or early satiety.” 1

Causes 1. Organic gastro-duodenal disease 2. Gastro-oesophageal reflux disease 3. Biliary tract and pancreatic disease 4. Functional or Non-ulcer dyspepsia

The following represents a guideline for management of patients in a primary care setting: 1-5 • Prompt investigation is recommended for patients with “warning” features since there is a high likelihood of gastric pathology (benign or malignant). These “warning” features include: 1. Age >45 yrs and recent onset of symptoms 2. Daily constant pain 3. Weight loss 4. NSAID use 5. Vomiting 6. Past history of gastric ulcer or gastric surgery 7. Anaemia 8. Dysphagia 9. Bleeding • Endoscopy is the recommended method of investigation (barium meal is an alternative, if endoscopy unavailable). 3 • Younger patients who do not display “warning” features have a very low risk of gastric malignancy and may be investigated for Helicobactor pylori by serology or breath test; patients who are negative may be treated symptomatically 6; positive patients may be treated with H. pylori eradication therapy or may be investigated by barium meal or endoscopy. 7,8 • Failure to respond to empirical therapy is an indication for further investigation.

UPPER GASTROINTESTINAL ENDOSCOPY • Endoscopy is the test of choice to exclude gastro-duodenal ulceration, reflux oesophagitis, and upper gastro-intestinal tract malignancy. 9 • Superior diagnostic accuracy compared to double contrast barium meal (96% vs 70%) in detecting structural causes of dyspepsia. 9 • Advantages: ability to biopsy lesions suspicious for malignancy and to perform invasive tests for H. pylori infection.

DOUBLE CONTRAST BARIUM MEAL (DCBM) • Preferred in patients with a contra-indication to endoscopy. 10 • High sensitivity for diagnosis of gastric carcinoma and gastric ulcers. 10,11 • Particular strengths in the diagnosis of minor strictures, motility disorders, extrinsic and possible intramural abnormalities, as well as the diagnosis of malrotations, herniations and other structural abnormalities. • Advantages: no sedation. • Limitations: Inability to show subtle mucosal lesions. 9,12 • Disadvantages: exposure to ionising radiation.

138 OTHER IMAGING • Ultrasound is the investigation of choice for suspected gallbladder or biliary pathology. • Ultrasound of gallbladder has a low yield (1-3%) in dyspepsia and the finding of gallstones is usually incidental. 13 • If pancreatic disease is suspected, CT is advised.

139 REFERENCES 1. Veldhuyzen van Zanten SJO, Flook N, Chiba N, et al. An Evidence based approach to the management of uninvestigated dyspepsia in the era of Helicobacter pylori. CMAJ 2000; 162(12 Suppl): 3-23. 2. Talley NJ, Silverstein MD, Agreus L, et al. AGA technical review: Evaluation of dyspepsia. Gastroenterology 1998; 114:582-595. 3. British Society of Gastroenterology. Dyspepsia management guidelines. 4. Talley NJ, Lam SK, Goh KL, et al. Management guidelines for uninvestigated and functional dyspepsia in the Asia-Pacific region: First Asian Pacific working party on functional dyspepsia. J Gastroenterol & Hepatology 1998; 13: 335-353. 5. Smucny J. Evaluation of the patient with dyspepsia. J Fam Pract 2001; 50(6): 538- 543. 6. Asante MA, Mendall M, Patel P, et al. A randomised trial of endoscopy vs no endoscopy in the management of seronegative Helicobacter pylori dyspepsia. Eur J Gastroenterol Hepatol 1998; 10: 983-89. (Level I evidence) 7. Lassen AT, Pedersen FM, Bytzer P, et al. Helicobacter pylori test and eradicate versus prompt endoscopy for management of dyspeptic patients: a randomised trial. Lancet 2000; 356: 455-460. (Level I evidence) 8. Heaney A, Collins JSA, Watson RGP, et al. A prospective randomised trial of a “test and treat” policy versus endoscopy based management in young Helicobacter pylori positive patients with ulcer-like dyspepsia, referred to a hospital clinic. Gut 1999; 45: 186-190. (Level I evidence) 9. Dooley CP, Larson AW, Stace NH, et al. Double contrast barium meal and upper gastrointestinal endoscopy. Annals of Internal Medicine 1984; 101: 538-545. (Prospective double blind study 100 randomly selected inpatients - Level I evidence). 10. Shaw PC, van Romunde LKJ, Griffioen G, et al. Peptic ulcer and gastric carcinoma: diagnosis with biphasic radiography compared with fibreoptic endoscopy. Radiology 1987; 163: 39-42. (Prospective blinded study 385 patients with dyspepsia – Level II evidence) 11. Low VH, Levine MS, Rubesin SE, et al. Diagnosis of gastric carcinoma: sensitivity of double-contrast barium studies. AJR 1994; 162: 329-334. (Retrospective study 80 case controls with gastric carcinoma – Level IV evidence) 12. Shindoh N, Nakagawa T, Ozaki Y, et al. Overlooked gastric carcinoma: pitfalls in upper gastrointestinal radiology. Radiology 2000; 217; 409-414. (Retrospective study 24 patients – Level IV evidence) 13. Heikkinen MT, Pikkarainen PH, Takala JK, et al. Diagnostic methods in dyspepsia: the usefulness of upper abdominal ultrasound and gastroscopy. Scand J Prm Health Care 1997; 15: 82-86. (Prospective study 400 consecutive patients – Level II evidence)

140 DYSPHAGIA

CLINICAL ASSESSMENT • Dysphagia may be due to abnormalities of function (neuromuscular) or structure (benign or malignant strictures, etc). 1, 2 • The diagnostic approach to the dysphagic patient is multi disciplinary and imaging studies and endoscopy are complementary. 1, 2 • There is no evidence to support the use of either barium swallow or endoscopy as a preferred initial investigation for the evaluation of dysphagia. Both have different strengths and weaknesses. Clinical assessment and availability of the tests often helps direct which test to use first. 3

BARIUM SWALLOW STUDY +/- VIDEOFLUOROSCOPY • Examination is tailored to the patient’s symptoms. A double contrast barium study demonstrates mucosal abnormalities and a single contrast study best shows strictures, schatzki rings and oesophageal dysmotility. 1, 2 • Videofluoroscopy assesses oropharyngeal function and oesophageal motility. 4, 5 • Symptoms of mid/distal oesophageal causes of dysphagia may be referred to the pharynx, but the reverse is rare. However, distal lesions may be associated with cricopharyngeal abnormalities (eg Zenker’s diverticulum and distal stricture). 1,2 • Videofluoroscopy usually includes some assessment of all phases of swallowing and may require assessment with various consistencies of bolus, dependant on the

141 patient’s symptoms. Evidence of gastro-oesophageal reflux and the rate of clearing of the refluxate from the oesophagus are also documented. 5 • Overall sensitivity of 75-90% for the diagnosis of oesophageal motility disorders in comparison to oesophageal manometry. 6-9 • Videofluoroscopy is the investigation of choice in stroke patients with dysphagia. 10 • In many tertiary institutions, radiologists work closely with speech pathologists in a “dysphagia” clinic for the investigation of patients with oropharyngeal swallowing difficulties. Part of the assessment of such patients includes a videofluoroscopic study of swallowing to various consistencies of bolus which allows therapeutic decision making in regards to the level of consistency to use. • Advantages: • More sensitive than endoscopy for detection of lower oesophageal rings and strictures. 7,11 • Allows assessment of motility. • Less expensive and invasive, and more readily available compared to endoscopy. • Limitations: lack of direct visualisation of mucosa.

GASTRO-OESOPHAGEAL ENDOSCOPY • Best method to detect mucosal or structural abnormalities of the oesophagus and proximal stomach. 12 • In the assessment of dysphagia, primary role of endoscopy is to exclude malignant cause. • Advantages: • Allows biopsies to be taken. • Allows therapeutic intervention at same setting eg dilatation of strictures. • More sensitive than barium swallow study for diagnosing of mild reflux oesophagitis or other subtle forms of oesophagitis. 7 • Limitations: • More expensive and invasive than barium swallow study. • Inferior to barium studies for detection of lower oesophageal rings or strictures. 7,11 • Inability to evaluate oesophageal motility disorders. 7

MANOMETRY • “Gold standard” for diagnosis of oesophageal motility disorders, especially achalasia. 13,14 • Measures the amplitude, timing, and configuration of oesophageal contractions and evaluates Lower oesophageal sphincter (LES) function. 13 • Routine use is not indicated because of the low specificity of the findings and low likelihood of detecting a clinically significant motility disorder. 13 • Indications include: 13,14 1. When abnormality is not identified on barium study or by endoscopy and correct diagnosis is essential and/or for which localisation of LES is important. 2. To establish the diagnosis of suspected cases of achalasia or diffuse oesophageal spasm. 3. To detect oesophageal motor abnormalities associated with systemic diseases (eg connective tissue diseases) if their detection would contribute to establishing a mutisystem diagnosis or to other aspects of management. • Disadvantages: invasive, patient discomfort and limited availability.

142 COMPUTED TOMOGRAPHY • Best investigation for assessment of extrinsic stricture due to mediastinal disease and for tumour staging prior to surgery.

ENDOSCOPIC ULTRASOUND • Allows visualisation of the deeper wall layers and perioesophageal tissues. • Useful in assessment of submucosal lesions (eg leiomyoma), mediastinal disease, and in locoregional staging of the oesophageal cancer. 15

RADIONUCLIDE OESOPHAGEAL TRANSIT STUDIES • Simple, non-invasive method for assessing motility disorders and quantifying oesophageal emptying, and gastro-oesophageal reflux. • Overall sensitivity of 68% for diagnosing oesophageal motility disorders using manometry as standard. 6,16 • Provides information on bolus transit through the oesophagus that can complement manometric data. • Useful for diagnosis of oesophageal involvement in systemic diseases, such as scleroderma or autonomic neuropathy.

143 REFERENCES 1. Baker ME, Rice TW. Radiologic evaluation of the : methods and value in motility disorders and GERD. Seminars in Thoracic and Cardiovascular Surgery 2001; 13 (3): 201-225. 2. Levine MS, Rubesin SE. Radiologic investigation of dysphagia. AJR 1990; 154: 1157-1163. 3. Spechler SJ. AGA technical review of treatment of patients with dysphagia caused by benign disorders of the distal esophagus. Gastroenterology 1999; 117: 233-254. 4. Schima W, Pokieser P, Schober E, et al. Globus sensation: value of static radiography combined with videofluoroscopy of the pharynx and oesophagus. Clinical Radiology 1996; 51: 177-185. (Retrospective study cohort of 130 consecutive patients – Level II evidence) 5. Logemann JA. Role of the modified barium swallow in management of patients with dysphagia. Otolaryngol Head Neck Surg 1997; 116(3): 335-338. 6. Parkman HP, Maurer AH, Caroline DF, et al. Optimal evaluation of patients with nonobstructive esophageal dysphagia: manometry, scintigraphy, or videoesophagography? Digestive Diseases and Sciences 1996; 41: 1355-1368. (Prospective study 89 consecutive patients – Level II evidence) 7. Halpert RD, Feczko PJ, Spickler EM, et al. Radiological assessment of dysphagia with endoscopic correlation. Radiology 1985; 157: 599-602. (Retrospective study cohort of 450 consecutive patients – Level II evidence) 8. Schima W, Stacher G, Pokieser P, et al. Esophageal motor disorders: videofluoroscopic and manometric evaluation – prospective study in 88 symptomatic patients. Radiology 1992; 185: 487- 491. (Prospective study 92 consecutive patients – Level II evidence) 9. Ott DJ, Richter JE, Chen YM, et al. Esophageal radiography and manometry: correlation in 172 patients with dysphagia. AJR1987; 149: 307-311. (Retrospective study cohort of 172 consecutive patients – Level II evidence) 10. Perry L, Love CP. Screening for dysphagia and aspiration in acute stroke: a systematic review. Dysphagia 2001; 16: 7-18. 11. Dooley CP, Larson AW, Stace NH, et al. Double-contrast barium meal and upper gastrointestinal gastroscopy: a comparative study. Ann Intern Med 1984; 101: 538- 545. (Prospective study 100 randomly selected patients – Level II evidence) 12. Cooper GS. Indications and contraindications for upper gastrointestinal endoscopy. Gastrointest Endosc Clin N Am 1994; 4: 439-454. 13. Kahrilas PJ, Clouse RE, Hogan WJ. American Gastroenterology Association technical review on the clinical use of oesophageal manometry. Gastroenterology 1994; 107: 1865-1884. 14. Feussner H, Kauer W, Siewert JR. The place of esophageal manometry in the diagnosis of dysphagia. Dysphagia 1993; 8: 98-104. 15. Kelly S, Harris KM, Berry E, et al. A systematic review of the staging performance of endoscopic ultrasound in gastro-oesophageal carcinoma. Gut 2001; 49: 534-539. 16. Tatsch K, Voderholzer WA, Weiss MJ, et al. Reappraisal of quantitative esophageal scintigraphy by optimizing results with ROC analyses. J Nucl Med 1996; 37: 1799- 1805. (Cohort of 47 consecutive patients – Level II evidence)

144 IMAGING PRIOR TO LAPAROSCOPIC CHOLECYSTECTOMY

This is a controversial subject, and practices are likely to vary widely. Factors, which affect local practice, include: • Is the surgeon skilled at laparoscopic removal of common bile duct (CBD) stones? If so, then in most cases, even in patients with a high preoperative probability of CBD stones, no preoperative imaging may be required, the surgeon relying on intra- operative cholangiography for diagnosis. • Is the surgeon skilled in the performance of intra-operative cholangiography, but unable to perform laparoscopic removal of CBD stones? In this case, (which is perhaps the most common scenario in Australia at present) the pathway depicted in these guidelines is suggested i.e for patients with CBD stones on intra-operative cholangiography, post-operative Endoscopic Retrograde Cholangiography (ERCP) and stone extraction is carried out, or there is conversion of the surgical procedure to open operation and common duct exploration.

145 • Does the surgeon wish to know the biliary anatomy and whether any anomalies exist prior to surgery? If so, imaging with intravenous cholangiography (IVC) or CT cholangiography may be indicated.

RISK ASSESSMENT FOR COMMON BILE DUCT STONES • Presence of ductal stones in patients with cholelithiasis can be predicted with fair accuracy by applying clinical, biochemical and ultrasonographic criteria (size of the common bile duct). 1,2 • Based on these criteria, patients planned for laparoscopic cholecystectomy can be stratified into three main groups: 3 1. High risk 2. Intermediate/Medium risk 3. Low risk • Many surgeons would incorporate the intermediate group into the low risk and manage those patients accordingly.

ULTRASONOGRAPHY • Low sensitivity (36%) but high specificity (98%) for detection of CBD stones. 4-7 • High sensitivity (95%) for biliary duct dilation but dilatation alone is not a specific marker of CBD stones. 5,6,11 • Limitations: false negatives due to inability to see the extra-hepatic biliary tree (often because of interposed bowel gas), and absence of biliary dilation in the presence of obstruction. 8 • Advantages: quick, non-invasive, inexpensive, no ionising radiation, readily available.

ENDOSCOPIC RETROGRADE CHOLANGIOPANCREATOGRAPHY (ERCP) • Routine use of ERCP to detect common bile duct stones before laparoscopic cholecystectomy is not indicated in low risk groups. 3,9,11 • ERCP is indicated before laparoscopic cholecystectomy in patients in whom there is high clinical suspicion of choledocholithiasis, based on clinical, biochemical and ultrasonographic criteria. 3,10-13 • Highly accurate in diagnosis and treatment of common bile duct stones (96% success rate for endoscopic sphincterotomy). 3,10-12,14 • Limitations: up to 5% complication rate (eg pancreatitis), ~0.5-1% mortality rate and ~8% cannulation failure rate. 11-13,15

PREOPERATIVE INTRAVENOUS CHOLANGIOGRAPHY • Routine use is not indicated. 12,16 • Used by some surgeons in low risk patients to detect anatomical variants and common bile duct stones. 16,17 • Limitations: • Potential risk of contrast toxicity. 12 • Does not offer therapeutic opportunity

146 ENDOSCOPIC ULTRASOUND (EUS) • Highly accurate (>95%) for the detection of choledocholithiasis (superior to CT and US). 3,4,6,7,18-21 • Comparable sensitivity to that of ERCP for detection of choledocholithiasis. 18,19 • Can be used to detect common bile duct stones in intermediate risk group who are good surgical candidates. 3,18,22 • Not suitable in: 19 • Severe acute biliary pancreatitis or cholangitis, since it may delay endoscopic treatment. • In elderly and high-risk surgical patients because in this population the treatment of choice is endoscopic sphincterotomy if CBD stones are detected. • Limitations: limited availability, invasive, technically impossible in cases of previous gastric surgery, difficult to interpret following sphincterotomy or previous biliary stenting procedures due to presence of air in the biliary tract, and does not offer therapeutic opportunity.

MAGNETIC RESONANCE PANCREATOCHOLANGIOGRAPHY (MRCP) • >95% sensitivity and specificity for detection of choledocholithiasis. 21, 23-25 • Can be used in intermediate risk group. 23, 24 • Advantages: non-invasive, no ionising radiation or contrast material and allows diagnosis and treatment planning in many patients without invasive cholangiography. • Limitations: does not offer therapeutic opportunity, expensive and limited availability

CT CHOLANGIOGRAM • >90% sensitivity and specificity for detection of bile duct stones. 25-27 • Alternative for detection of CBD stones in intermediate risk group, if MRCP or EUS unavailable. 25-27 • Used by some surgeons, to evaluate aberrant bile ducts before laparoscopic cholecystectomy. 28 • Disadvantages: • Unsuccessful if abnormal liver function tests. • Potential risk of contrast toxicity. • Radiation exposure. • Does not offer therapeutic opportunity.

147 REFERENCES 1. Abboud PA, Malet PF, Berlin JA, et al. Predictors of common bile duct stone prior to cholecystectomy: a meta-analysis. Gastrointest Endosc 1996; 44: 450-459. (Meta- analysis 22 studies - Level II evidence) 2. Kama NA, Atil M, Doganay M, et al. Practical recommendations for the prediction and management of common bile duct stones in patients with gallstones. Surg Endosc 2001; 15: 942-945. (Prospective database of 986 patients – Level II evidence) 3. Berdah SV, Orsoni P, Bege T, et al. Follow-up of selective endoscopic ultrasonography and/or endoscopic retrograde cholangiography prior to laparoscopic cholecystectomy: a prospective study of 300 patients. Endoscopy 2001; 33: 216- 220. (Prospective study 300 patients – Level II evidence) 4. Canto MI, Chak A, Stellato T, et al. Endoscopic ultrsonography versus cholangiography for the diagnosis of choledocholithiasis. Gastrointest Endosc 1998; 47: 439-448. (Prospective blinded study 64 consecutive patients – Level II/III evidence) 5. Stott MA, Farrands PA, Guyer PB, et al. Ultrasound of the common bile duct in patients undergoing cholecystectomy. J Clin Ultrasound 1991: 19: 73-76. (Prospective study 100 patients – Level II/III evidence) 6. Sugiyama M, Atomi Y. Endoscopic Ultrasonography for diagnosing choledocholithiasis: a prospective comparative study with ultrasonography and computed tomography. Gastrintest Endosc 1997; 45: 143-146. (Prospective study 155 patients – Level II evidence) 7. Amouyal P, Amouyal G, Levy P, et al. Diagnosis of choledocholithiasis by endoscopic ultrasonography. Gastroenterology 1994; 106: 1062-1067. (Prospective study 62 consecutive patients – Level II/III evidence) 8. Dong B, Chen M. Improved sonographic visualisation of choledocholithiasis. J Clin Ultrasound 1987; 15: 185-190. (Prospective study 4500 patients – Level II/III evidence) 9. Urbach DR, Khajanchee YS, Jobe BA, et al. Cost-effective management of common bile duct stones: a decision analysis of the use of endoscopic retrograde cholangiopancreatography (ERCP), intraoperative cholangiography, and laparoscopic bile duct exploration. Surg Endosc 2001; 15: 4-13. (Decision analysis – Level III evidence) 10. Cuschieri A, Lazoche E, Morino M, et al. E.A.E.S multicenter prospective randomized trial comparing two-stage vs single-stage management of patients with gallstone disease and ductal calculi. Surg Endosc 1999; 13: 952-957. (Prospective randomised trial of 300 patients - Level II evidence) 11. Neuhaus H, Feussner H, Ungeheuer A, et al. Prospective evaluation of the use of endoscopic retrograde cholangiography prior to laparoscopic cholecystectomy. Endoscopy 1992: 24: 745-749. (Prospective study 288 patients – Level II/III evidence) 12. Rieger R, Wayand W. Yield of prospective, noninvasive evaluation of the common bile duct combined with selective ERCP/sphincterotomy in 1390 consecutive laparoscopic cholecystectomy patients. Gastrointestinal Endoscopy 1995; 42: 6-12. (Prospective study 1390 consecutive patients - Level II/III evidence) 13. Rijna H, Borgstein PJ, Meuwissen SGM, et al. Selective preoperative endoscopic retrograde cholangiopancreatography in laparoscopic biliary surgery. Br J Surg 1995; 82: 1130-1133. (Prospective study 119 patients – Level II/III evidence) 14. Bergamschi R, tuech JJ, Braconier L, et al. Selective endoscopic retrograde cholangiography prior to laparoscopic cholecystectomy for gallstones. Am J Surg 1999; 178: 46-49. (Prospective study 990 patients – Level II evidence)

148 15. Freeman ML, Nelson DB, Sherman S, et al. Complications of endoscopic biliary sphincterotomy. NEJM 1996; 335: 909-918. (Prospective cohort study 2347 patients – Level II evidence). 16. Tham TCK, Collins JSA, Watson RGP, et al. Diagnosis of common bile duct stones by intravenous cholangiography: prediction by ultrasound and liver tests compared with endoscopic retrograde cholangiography. Gastrointest Endosc 1996; 44: 158- 163. (Prospective study 81 consecutive non-jaundiced patients – Level III evidence) 17. Berggren P, Farago I, Gabrielsson, et al. Intravenous cholangiography before 1000 consecutive laparoscopic . Br J Surg 1997; 84: 472-476. (Prospective study 1000 consecutive patients – Level II evidence) 18. Palazzo L, Girollet PP, Salmeron M, et al. Value of endoscopic ultrasonography in the diagnosis of common bile duct stones: comparison with surgical exploration and ERCP. Gastrointest Endosc 1995; 42: 225-231.(Retrospective study 422 patients – Level II/III evidence) 19. Prat F, Amouyal G, Amouyal P, et al. Prospective controlled study of endoscopic ultrasonography and endoscopic retrograde cholangiography in patients with suspected common bile duct lithiasis. Lancet 1996; 347: 75-79. (Prospective study 119 patients – Level II/III evidence) 20. Aubertin JM, Levoir D, Bouillot JL, et al. Endoscopic ultrasonography immediately prior to laparoscopic cholecystectomy: a prospective evaluation. Endoscopy 1996; 28: 667-673. (Prospective study 50 patients – Level II/III evidence) 21. De Ledinghen V, Lecesne R, Raymond JM, et al. Diagnosis of choledocholithiasis: EUS or magnetic resonance cholangiography? A prospective controlled study. Gastrointest Endosc 1999; 49: 26-31. (Prospective controlled study 32 patients – Level III evidence) 22. Sahai AV, Mauldin PD, Marsi V, Hawes RH, et al. Bile duct stones and laparoscopic cholecystectomy: a decision analysis to assess the roles of intraoperative cholangiography, EUS, and ERCP. Gastrointest Endosc 1999; 49: 334-343. (Decision analysis – Level II/III evidence) 23. Demartines N, Eisner L, Schnabel K, et al. Evaluation of magnetic resonance cholangiography in the management of bile duct stones. Arch Surg 2000; 135: 148- 152. (Prospective study 70 patients – Level II/III evidence) 24. Dwerryhouse SJ, Brown E, Vipond MN, et al. Prospective evaluation of magnetic resonance cholangiography to detect common bile duct stones before laparoscopic cholecystectomy. Br J Surg 1998; 85: 1364-1366. (Prospective study 40 patients – Level II/III evidence) 25. Soto JA, Alvarez O, Munera F, et al. Diagnosing bile duct stones: comparison of unenhanced helical CT, oral contrast enhanced CT cholangiography, and MR cholangiography. AJR 2000; 175: 1127-1134. (Retrospective study 51 patients jaundiced patients excluded ERCP SR – Level III evidence) 26. Polkowski M, Palucki J, Regula J, et al. Helical computed tomographic cholangiography versus endosonography for suspected bile duct stones: a prospective blinded study in non-jaundiced patients. Gut 1999; 45: 744-749. (Prospective study 52 patients – Level II/III evidence) 27. Van Beers BE, Lacrosse M, Trigaux JP, et al. Noninvasive imaging of the biliary tree before or after laparoscopic cholesystectomy: use of three-dimensional spiral CT cholangiography. AJR 1994; 162: 1331-1335. (Prospective study 24 patients – Level III evidence) 28. Hirao K, Miyazaki A, Fujimoto T, et al. Evaluation of aberrant bile ducts before laparoscopic cholecystectomy: helical CT cholangiography versus MR cholangiography. AJR 2000; 175: 713-720. (Prospective study 16 patients - Level III evidence)

149 Further Reading 1. Shah SK, Mutignani, Costamagna G, et al. Therapeutic Biliary endoscopy. Endoscopy 2002; 34(1): 43-53. 2. Palazzo L. Which test for common bile duct stones? Endoscopic and intraductal ultrasonography. Endocopy 1997; 29: 655-665.

150 INVESTIGATION OF CHOLESTATIC JAUNDICE

151 CHOLESTATIC JAUNDICE • Diagnostic approach for cholestatic jaundice depends on: • Clinical probability of whether the most likely cause is benign or malignant, • Whether the patient is a surgical candidate, once the diagnosis is made, • Availability of each possible imaging modalities and the expertise with which they are offered. 1

ULTRASOUND (US) • Initial investigation of choice for the aetiological diagnosis of cholestasis. 2, 3 • Determines the presence of cholestatic jaundice by detecting dilated bile ducts (sensitivity >90% and specificity of 71-96%). 2, 4 • Advantages: non-invasive, no ionising radiation, relatively inexpensive, and can visualise the whole hepatic parenchyma. • Limitations: • Less effective than CT, EUS or direct cholangiography (ERCP or PTC) in determining the site and cause of obstruction. 3,4 • Less accurate at detecting common bile duct stones (sensitivity 55% and specificity 98%). 5 • False negatives due to inability to see the extra-hepatic biliary tree (often because of interposed bowel gas), and absence of biliary dilation in the presence of obstruction. 6

COMPUTED TOMOGRAPHY (CT) • Indications: • Cause of obstruction unidentified on US and there is high clinical suspicion of malignant obstruction. 3 • Staging and determining the resectability of malignant biliary disease. 7 • Compared to US, CT provides a more comprehensive examination that permits evaluation of the liver, biliary tree, pancreas, portal and retroperitoneal lymph nodes, and vascular structures. 7 • 76-88% sensitivity and 98% specificity for common bile duct stones. 5, 8 • Limitations: 5, 8 • False negatives due to non-enlarged common bile ducts or small stones. • False positives due to pancreatic calcifications.

ENDOSCOPIC RETROGRADE CHOLANGIOPANCREATOGRAPHY (ERCP) • “Gold standard” for visualising the biliary tract and for defining the cause of obstruction. 2, 3, 10 • If there is strong suspicion of common bile duct stones and initial imaging investigations with US or CT are negative or equivocal, then ERCP is indicated. 9 • Preferred in patients who are poor surgical candidates or in whom sclerosing cholangitis is suspected (high likelihood of depicting the biliary tree, diagnoses and treatment of strictures). 10 • Advantages: provides greater range and ease of therapeutic options for relief of the obstruction. • Disadvantages: invasive procedure with significant risk of complications (pancreatitis, perforation, haemorrhage etc) and mortality (<1%) and 3-10% failure rate. 11, 12

152 PERCUTANEOUS TRANSHEPATIC CHOLANGIOGRAPHY (PTC) • Alternative if ERCP is technically not feasible or not available. • Advantages: • Permits visualisation of the intra-hepatic and extra-hepatic biliary tree. • Provides portal for biliary drainage and interventional procedures if obstruction is found. • Disadvantages: does not opacify the pancreatic duct, expensive and invasive procedure with significant risk of complications (risk of hepatic puncture, pneumothorax, etc) and mortality. 13

MAGNETIC RESONANCE CHOLANGIOPANCREATOGRAPHY (MRCP) • Non-invasive alternative if ERCP is unsuccessful or inadequate or cannot be performed (eg in patients with previous gastroenteric anastomoses). 14-16 • High diagnostic accuracy (>94%) for the diagnosis of bile duct obstruction, choledocholithiasis, and malignant bile duct obstruction. 17-19 • Advantages: non-invasive, no ionising radiation or contrast material and allows diagnosis and treatment planning in many patients without invasive cholangiography. • Limitations: • Low spatial resolution. • Does not offer therapeutic opportunity.

ENDOSCOPIC ULTRASONOGRAPHY (EUS) • Best modality for tumour staging of malignant biliary obstruction (provided mass is not >3cm in size). 4, 20, 21 • Very sensitive for very small tumour detection. 20-22 • Used in patients who are good surgical candidates in order to stage a tumour or identify choledocholithiasis. 10, 20, 22 • Comparable sensitivity to that of ERCP for extrahepatic cholestasis. 4, 10, 23 • Superior to US or CT in diagnosis (100% sensitivity) and staging of biliary obstruction. 2, 4 • Limitations: limited availability, technically impossible in cases of previous gastric surgery, sometimes difficult to interpret following sphincterotomy or previous stenting procedures due to presence of air in the biliary tract, and does not offer therapeutic opportunity.

153 REFERENCES 1. American College of Radiology. Appropriateness criteria for imaging and treatment decisions. Imaging strategies in the evaluation of the jaundiced patient. American College of Radiology 1999; G125-133. 2. Amouyal P, Palazzo L, Amouyal G, et al. Endosonography: promising method for diagnosis of extrahepatic cholestasis. Lancet 1989; Nov 18: 1195-1198. (Prospective study 52 consecutive patients – Level II/III evidence) 3. Baron RL, Stanley RJ, Lee JKT, et al. A prospective comparison of the evaluation of biliary obstruction using computed tomography and ultrasonography. Radiology 1982; 145: 91-98. (Prospective study 103 consecutive patients – Level II/III evidence) 4. Dancygier GH, Natermann C. The role of endoscopic ultrasonography in the biliary tract diseases: obstructive jaundice. Endoscopy 1994; 26: 800-802. (Prospective study 41 patients - Level II/III evidence) 5. Amouyal P, Amouyal G, Levy P, et al. Diagnosis of choledocholithiasis by endoscopic ultrasonography. Gastroenterology 1994; 106: 1062-1067. (Prospective study 62 consecutive patients – Level II/III evidence) 6. Dong B, Chen M. Improved sonographic visualisation of choledocholithiasis. J Clin Ultrasound 1987; 15: 185-190. (Prospective study 4500 patients – Level II/III evidence) 7. Gulliver DJ, Baker ME, Cheng CA, et al. Malignant biliary obstruction: efficacy of thin-section dynamic CT in determining resectability. AJR 1992; 159: 503-507. (Retrospective study 67 patients – Level III evidence) 8. Neitich JD, Topazian M, Smith RC, et al. Detection of choledocholithiasis: comparison of unenhanced helical CT and endoscopic retrograde cholangiopancreatography. Radiology 1997; 203: 753-757. (Prospective study 51 patients – Level III evidence) 9. Borsch G, Wegener M, Wedmann B, et al. Clinical evaluation, ultrasound, cholescintgraphy and endoscopic retrograde cholangiography in cholestasis: a prospective comparative clinical study. J Clin Gastroenterol 1988; 10(2): 185-190. (Prospective study 72 patients – Level II/III study) 10. Burtin P, Palazzo L, Canard JM, et al. Diagnostic strategies for extrahepatic cholestasis of indefinite origin: endoscopic ultrasonography or retrograde cholagiography? Results of a prospective study. Endoscopy 1997; 29: 349-355. (Prospective study 68 patients – Level II/III evidence) 11. Bilbao MK, Dotter CT, Lee TG, et al. Complications of endoscopic retrograde cholangiopancreatography (ERCP): a study of 10,000 cases. Gastroenterology 1976; 70: 314-320. (Level II evidence) 12. Freeman ML, DiSario JA, Nelson DB, et al. Risk factors of post-ERCP pancreatitis: a prospective multicenter study. Gastrointestinal Endosc 2001; 54: 425-434. (Prospective study 1963 consecutive ERCP procedures – Level II evidence) 13. Mueller PR, Harbin WP, Ferrucci JT Jr, et al. Fine needle transhepatic cholangiography: reflections after 450 cases. AJR 1981; 136(1): 85-90. (Cohort of 450 cases – Level III evidence) 14. Varghese JC, Farrell MA, Courtney G, et al. Role of MR cholangiopancreatography in patients with failed or inadequate ERCP. AJR 1999; 173: 1527-1533. (Prospective study 58 patients – Level II/III evidence) 15. Fulcher AS, Turner MA, Capps GW, et al. Half Fourier RARE MR cholangiopancreatography: experience in 300 patients. Radiology 1998; 207(1): 21- 32. (Prospective study 300 patients including 35 controls – Level II/III evidence)

154 16. Soto JA, Yucel EK, Barish MA, et al. MR cholangiopancreatography after unsuccessful or incomplete ERCP. Radiology 1996; 199: 91-98. (Prospective study 37 consecutive patients – Level II evidence) 17. Guibaud L, Bret PM, Reinhold C, et al. Bile duct obstruction and choledocholithiasis: diagnosis with MR cholangiography. Radiology 1995; 197: 109-115. (Prospective study 126 consecutive patients – Level II/III evidence) 18. Becker CD, Grossholz M, Becker M, et al. Choledocholithiasis and bile duct stenosis: diagnostic accuracy of MR cholangiopancreatography. Radiology 1997; 205: 523-530. (Retrospective study cohort of 108 patients – Level III evidence) 19. Soto JA, Barish MA, Yucel EK, et al. Magnetic resonance cholangiography: comparison with endoscopic retrograde cholangiopancreatography. Gastroenterology 1996; 110: 589-597. (Prospective study 46 patients – Level II evidence) 20. Rosch T, Braig C, Gain T, et al. Staging of pancreatic and ampullary carcinoma by endoscopic ultrasonography: comparison with conventional sonography, computed tomography, and angiography. Gastroenterology 1992; 102: 188-199. (Prospective study 60 consecutive patients – Level III evidence) 21. Tio TL, Sie LH, Kallimanis G, et al. Staging of ampullary and pancreatic carcinoma: comparison between endosonography and surgery. Gastrointest Endosc 1996; 44: 706-713. (Prospective study 102 patients – Level II/III evidence) 22. Napoleon B. Diagnosis of biliary lesions: role of endoscopic ultrasound in the diagnosis of cholestasis. Endoscopy 1998; 30(S1): A116-119. 23. Prat F, Amouyal G, Amouyal P, et al. Prospective controlled study of endoscopic ultrasonography and endoscopic retrograde cholangiography in patients with suspected common bile duct lithiasis. Lancet 1996; 347: 75-79. (Prospective study 119 patients – Level II/III study)

Further Reading 1. Barish MA, Yucel EK, Ferrucci JT. Magnetic resonance cholangiopancreatography. NEJM 1999; 341: 258-264.

155 STAGING OF COLORECTAL CANCER

COLORECTAL CANCER • A careful pre-operative search for systemic metastases is rarely indicated in colonic cancer patients as initial management is not often altered, since most colonic cancer patients benefit from resection of the primary lesion even if there are distant metastases. 1 • Pre-operative identification of liver/lung metastases may be useful in: 1 • Frail, elderly patients who may not need resection of a relatively asymptomatic primary tumour. • Patients with clinical indication of extensive local or systemic metastases as extensive (>50%) liver metastases carry a high operative mortality. • Patients for infusaport insertion for chemotherapy for hepatic metastases. • Occasional patients where primary resection of metastases is considered. • Preoperative locoregional staging of rectal cancer is important, both to plan surgery and to consider the possible need for adjuvant chemoradiotherapy. 1 • Routine chest radiographs and liver scan by CT or US are suggested at the primary presentation. 1

SCREENING FOR HEPATIC METASTASES • Liver ultrasound is usually used to screen for hepatic metastases (~66% sensitivity per patient basis) because it is relatively inexpensive, does not involve the use of contrast material, no exposure to ionising radiation and widely available. 2 • Some clinicians use CT to screen for hepatic metastases.

156 COMPUTED TOMOGRAPHY (CT) ABDOMEN • Routine CT is not indicated for staging of primary colorectal cancer unless clinically advanced. 3 • 70-80% sensitivity for hepatic metastases. 2, 4 • Procedure of choice for preoperative assessment of the abdomen and retroperitoneum in clinically advanced disease because of high negative predictive value and increasing accuracy in advanced disease. 4-6 • There is no advantage of MRI over CT for local staging of tumour. 2, 7 • Limitations: less reliable for local staging because of low sensitivity for detection of local tumour extent and lymph node metastases. 4, 6, 7

COMPUTED TOMOGRAPHY (CT) PELVIS • Useful in assessing the extent of pelvic disease in patients with a large bulky rectal cancer, especially in stenosing tumour that precludes endorectal US.

WORK UP OF PATIENT WITH HEPATIC METASTASES • In patients in whom primary resection of liver metastases is considered, further evaluation of hepatic metastases with spiral CT or CT arterial , may be required. • Spiral CT coupled with rapid injection of IV contrast is preferred technique for hepatic imaging and is more sensitive than conventional scanning for tumour detection and characterisation. 8, 9 • CT arterial portography (CTAP) is a useful procedure for assessing the resectability of hepatic metastases (high sensitivity for detection of hepatic metastases). But significant rate of false positives (due to artefacts), low specificity and invasive nature prevent its routine use. 2, 9, 10 • Recent studies suggest that F-18 fluorodeoxyglucose positron emission tomography (PET) is the most sensitive non-invasive imaging modality for the detection of hepatic metastases and if PET is unavailable then ferumoxide-enhanced magnetic resonance imaging (MRI) is recommended. 2

ENDORECTAL ULTRASOUND • “Gold standard” and preferred initial method for local staging of rectal carcinoma. 3 • High accuracy (85 - 95%) in evaluation of tumour penetration and perirectal spread. 11, 12 • Superior to CT or MRI in evaluation of both local tumour extent and lymph node involvement. 6, 13 • Limitations: less accurate in staging advanced tumours due to its limited depth penetration. 3

OBSTRUCTING OR POTENTIALLY OBSTRUCTING COLONIC CANCER • Metallic self-expanding stents are used for: 14-16 1. Palliation in patients with inoperable disease or distant metastases or who are unfit for surgery. 2. Temporary relief of obstruction to allow colonic preparation and primary anastomosis. • Stents can be inserted colonoscopically, under fluoroscopic guidance or combination.

157 REFERENCES 1. Guidelines for the prevention, early detection and management of colorectal cancer (CRC). National health and Medical Research Council 1999. 2. Kinkel K, Lu Y, Both M, et al. Detection of hepatic metastases from cancers of the gastrointestinal tract by using noninvasive imaging methods (US, CT, MRI imaging, PET): a meta-analysis. Radiology 2002; 224: 748-756. (Meta-analysis - Level II evidence) 3. Thoeni RF. Colorectal cancer: radiologic staging. Radiologic Clinics of North America 1997; 35(2): 457-485. 4. Balthazar EJ, Megibow AJ, Hulnick D, et al. Carcinoma of the colon: detection and preoperative staging by CT. AJR 1988; 150: 301-306. (Retrospective cohort 90 consecutive patients – Level II/III evidence) 5. Cance WG, Cohen AM, Enker WE, et al. Predictive value of a negative computed tomographic scan in 100 patients with rectal carcinoma. Dis Colon Rectum 1991; 34: 748-751. (Retrospective study cohort of 177 consecutive patients – Level II/III evidence) 6. Freeny PC, Marks WM, Ryan JA, et al. Colorectal carcinoma evaluation with CT: preoperative staging and detection of postoperative recurrence. Radiology 1986; 158: 347-353. (Prospective study 103 consecutive patients – Level II/III evidence) 7. Zerhouni EA, Rutter C, Hamilton SR, et al. CT and MR imaging in the staging of colorectal carcinoma: report of the Radiology Diagnostic Oncology Group II. Radiology 1996; 200: 443-451.(Prospective study 365 patients – Level II evidence) 8. Valls C, Andia E, Sanchez A, et al. Hepatic metastases from colorectal cancer: preoperative detection and assessment of resectability with helical CT. Radiology 2001; 218: 55-60. (Prospective study 157 consecutive patients – Level II evidence) 9. Valls C, Lopez E, Guma A, et al. Helical CT versus CT arterial portography in the detection of hepatic metastasis of colorectal carcinoma. AJR 1998; 170: 1341-1347. ( Prospective study 26 patients – Level III evidence) 10. Van Ooijen B, Oudkerk M, Schmitz PIM, et al. Detection of liver metastases from colorectal carcinoma: Is there a place for routine computed tomography arteriography? Surgery 1996; 119: 511-516. (Prospective study 60 consecutive patients – Level II evidence) 11. Boyce GA, Sivak MV, Lavery IC, et al. Endoscopic ultrasound in the pre-operative staging of rectal carcinoma. Gastrointestinal Endoscopy 1992; 38: 468-471. (Prospective study 45 patients – Level II/III evidence) 12. Nielsen MB, Qvitzau S, Pedersen JF, et al. Endosonography for preoperative staging of rectal tumours. Acta Radiologica 1996; 37: 799-803. (Prospective study 100 patients – Level II/III evidence) 13. Rifkin MD, Ehrlich SM, Marks G. Staging of rectal carcinoma: prospective comparison of endorectal US and CT. Radiology 1989; 170: 319-322. (Prospective study 102 consecutive patients – Level II evidence) 14. Martinez-Santos C, Lobato RF, Fradejas JM, et al. Self expandable stent before elective surgery vs emergency surgery for the treatment of malignant colorectal obstructions: comparison of primary anastomosis and morbidity rates. Dis Colon Rectum 2002; 45: 401-406. (Cohort of 72 consecutive patients – Level II/III evidence) 15. Wong KS, Cheong DMO, Wong D. Treatment of acute malignant colorectal obstruction with self-expandable metallic stents. ANZ J Surg 2002; 72: 385-388. (Cohort of 16 patients – Level III evidence) 16. Vrazaz JI, Ferris S, Bau S, et al. Stenting for obstructing colorectal malignancy: an interim or definitive procedure. ANZ J Surg 2002; 72: 392-396. (Cohort of 12 patients – Level III evidence)

158 Further Reading 1. Van Erkel AR, Pijl MEJ, Van den Berg-Huysmans, et al. Hepatic metastases in patients with colorectal cancer: relationship between size of metastases, standard of reference, and detection rates. Radiology 2002; 224: 404-409.

159 STAGING OF OESOPHAGEAL CANCER

STAGING OF OESOPHAGEAL CANCER • Staging of oesophageal malignancy is aimed at assessing the extent of local invasion of the primary tumour through the oesophageal wall (T stage), and the presence or absence of local nodal (N stage) or distant metastases (M stage). 1

Stage Disease extent Tis Carcinoma insitu T1 Mucosal +/- submucosal involvement T2 Muscularis propria involvement T3 Peri-oesophageal adventitia involvement T4 Involvement of adjacent structures N0 No nodal involvement N1 Nodal involvement M1 Distant metastases

• Plain chest radiographs can be used to screen for pulmonary or mediastinal disease. 2

160 COMPUTED TOMOGRAPHY OF CHEST AND ABDOMEN (CT) • Initial staging test of choice for oesophageal cancer. 2, 3 • Useful for exclusion of T4 oesophageal cancers, as demonstrated by the preservation of fat planes between the oesophageal cancer and adjacent structures. 4 • If CT shows advanced local disease or distant metastases, no further staging is required, as palliative treatment is the only option. 5 • Limitations: less sensitive in differentiating the layer of the oesophageal wall (T status) or accurately assessing regional lymph node disease (N status). Therefore, if there is no evidence of metastatic disease on CT, endoscopic ultrasound should be performed to achieve the most accurate regional staging. 2, 6, 7

ENDOSCOPIC ULTRASOUND (EUS) • Most accurate non-invasive method for locoregional staging of oesophageal cancer. 8 • Indicated in patients with oesophageal cancer in whom a CT scan has ruled out T4 and M1 disease. 4 • Limitations: 8 • Incomplete examinations due to impassable stenosing tumours (which may be overcome by the use of recently available “miniprobes”). 9 • Difficulties with specificity for nodal involvement (reactive versus malignant). However, it can be overcome by the ability to combine fine –needle aspiration with EUS, allowing histological verification of identified lymph nodes. 10 • Note: suspicion of tracheo-bronchial involvement may require or bronchoscopic ultrasonography. 11

POSITRON EMISSION TOMOGRAPHY (PET) • Useful for detecting radiographically occult distant metastatic disease. 12-15 • Higher accuracy for diagnosing distant metastatic disease compared to the combination of CT and EUS. 12-17 • Improves diagnostic specificity for lymph node staging. 16, 17 • Limitations: 12-17 • Inability to determine T stage of the oesophageal tumour. • Inaccurate in the detection of local lymph node metastases. • Lack of anatomical detail. • Expensive and limited availability.

161 REFERENCES 1. The New TNM classification in gastroenterology (1997). Endoscopy 1998; 30(7): 643-649. 2. Lightdale CJ. American College of Gastroenterology: Practice guidelines. Esophageal Cancer. Am J Gastroenterology 1999; 94: 20-29. 3. Hadzijahic N, Wallace MB, Hawes RH, et al. CT or EUS for the initial staging of oesophageal cancer? A cost minimisation analysis. Gastrointestinal Endoscopy 2000; 52: 715-720. 4. Rice TW. Clinical staging of esophageal carcinoma: CT, EUS, and PET. Chest Surg Clin of North America 2000; 10(3): 471-485. 5. Fockens P, Kisman K, Merksu MP, et al. The prognosis of oesophageal carcinoma staged irresectable (T4) by endosonography. J Am Coll Surg 1998; 186: 17-23. 6. Botet JF, Lightdale CJ, Zauber AG, et al. Preoperative staging of oesophageal cancer: comparison of endoscopic US and dynamic CT. Radiology 1991; 181: 419- 425. (Prospective study 50 consecutive patients – Level II/III evidence) 7. Vilgrain V, Mompoint D, Palazzo L, et al. Staging of Esophageal carcinoma: comparison of results with endoscopic sonography and CT. AJR 1990; 155: 277- 281. (Prospective study 46 patients – Level II evidence) 8. Kelly S, Harris KM, Berry E, et al. A systematic review of the staging performance of endoscopic ultrasound in gastro-oesophageal carcinoma. Gut 2001; 49: 534-539. (Level II evidence) 9. Bowrey DJ, Clark GWB, Roberts SA, et al. Endosonographic staging of 100 consecutive patients with esophageal carcinoma: introduction of the 8-mm esophagoprobe. Diseases of the Esophagus 1999; 12: 258-263. (Prospective study with 100 consecutive patients- Level II evidence) 10. Vazquez-Sequeiros E, Norton ID, Clain JE, et al. Impact of EUS-guided fine needle aspiration on lymph node staging in patients with oesophageal carcinoma. Gastrointestinal Endoscopy 2001; 53: 751-757. (Retrospective study 74 patients – Level III evidence) 11. Nishimura Y, Osugi H, Inoue K, et al. Bronchoscopic ultrasonography in the diagnosis of tracheobronchial invasion of esophageal cancer. J Ultrsound Med 2002; 21: 49-58. (Prospective study 59 patients - Level II/III evidence) 12. Block MI, Patterson GA, Sundaresan RS, et al. Improvement in staging of oesophageal cancer with the addition of positron emission tomography. Ann Thorac Surg 1997; 64: 770-777. (Prospective study 58 patients- Level II/III evidence) 13. Luketich JD, Schauer PR, Meltzer CC, et al. Role of positron emission tomography in staging oesophageal cancer. Ann Thorac Surg 1997; 64: 765-769. (Retrospective study 35 patients - Level III evidence) 14. Kole AC, Plukker JT, Nieweg OE, et al. Positron emission tomography for staging of oesophageal and gastroesophageal malignancy. Br J Cancer 1998; 78: 521-527. 15. Luketich JD, Friedman DM, Weigel TL, et al. Evaluation of distant metastases in esophageal cancer: 100 consecutive positron emission tomography scans. Ann Thorac Surg 1999; 68: 1133-1137. 16. Flamen P, Lerut A, van Custem E, et al. Utility of positron emission tomography for the staging of patients with potentially operable esophageal carcinoma. J Clin Oncology 2000; 18(18): 3202-3210. (Prospective study 74 patients – Level II/III evidence) 17. Meltzer CC, Luketich JD, Friedman D, et al. Whole-body FDG positron emission tomographic imaging for staging esophageal cancer: comparison with computed tomography. Clinical Nuclear Medicine 2000; 25(11): 882-887. (Retrospective study cohort of 77 patients – Level III evidence)

162 SUSPECTED BOWEL OBSTRUCTION

PLAIN RADIOGRAPHY • Initial imaging study for confirming bowel obstruction, defining the approximate level of obstruction and very rarely may show the likely cause eg gallstone ileus, incarcerated , closed loop obstruction/volvulus and ischaemic bowel. 1-4 • 60-70% sensitivity for detection of small bowel obstruction. 1, 5 • Performs better in high-grade obstruction. 1 • Findings suggesting the diagnosis of small bowel obstruction include: 1, 2 • Distended loops of small bowel. • Collapsed colon. • The “string of pearls” sign resulting from the small amount of residual air compared with the large amount of retained fluid. • Pseudotumor related to distended fluid filled loops. 163 • ~ 80% sensitivity for detecting and predicting the level of large bowel obstruction. 6, 7 • In large bowel obstruction, it is important to note the degree of caecal distension on the plain abdominal films, since marked distension will point to the need for urgent decompression (by surgery or other intervention) to prevent caecal perforation. • Limitations: 1, 2 • Fails to diagnose the cause of obstruction in most cases. • In obstruction of ileocaecal region, it may be difficult to determine whether the level is in the proximal large bowel or distal ileum. • Cannot reliably detect the presence of ischaemic complications.

COMPUTED TOMOGRAPHY IN EVALUATION OF SMALL BOWEL OBSTRUCTION (SBO) • Imaging modality of choice when plain abdominal radiography depicts distended small bowel and further imaging is indicated. 1-4, 8 1, 3, 9, 10 • 90-96% sensitivity for detection of acute high-grade obstruction. • Useful in: 4 • Confirming or excluding small bowel obstruction (versus pseudo-obstruction). 1, 3, 11 • Defining the degree and site of obstruction. 1, 8, 11 • Identifying the cause of small bowel obstruction (73-95% sensitivity). 1, 3, 8, 10, 12 • Confirming or excluding the diagnosis of ischaemia (>90% sensitivity and specificity). 11-13 • Advantages: 4 • Superior to enteroclysis in showing extraluminal masses, revealing abscesses, malignancy, anterior adhesions as well as features of strangulation. 3 • Ability to depict other causes of an acute abdomen. • Limitations: • Low sensitivity (48%) for detection and location of low-grade small bowel obstruction. 1, 9, 10

COMPUTED TOMOGRAPHY IN EVALUATION OF LARGE BOWEL OBSTRUCTION (LBO) • Indicated as an alternative to contrast enema in evaluation of large bowel obstruction in: 1. Very elderly and/or immobile patients. 14 2. If there are clinical indicators that large bowel obstruction is more likely due to diverticulitis. 3. If there is suspicion of local perforation. 4. Where contrast enema cannot be tolerated. 5. When there is clinical or plain AXR suspicion of bowel ischaemia proximal to 14, 15 obstruction.

ENTEROCLYSIS • Imaging modality of choice for evaluation of low-grade or intermittent small bowel obstruction. 2, 4 • Advantages: • Superior to CT in diagnosis and defining the location of the low-grade obstruction. 16 • Has the ability to gauge the severity of obstruction objectively. 5 • Findings in small bowel obstruction include: 2

164 • Dilatation of loops of small bowel. • Delayed transit time of the barium to a point of transition in the calibre of the bowel lumen. • Limitations: 2 • Need for nasoenteric intubation. • Time required for contrast to reach the obstruction. • Dilution of barium because of excess residual intraluminal fluid. • Demonstration of extrinsic causes is sometimes difficult. • Contraindicated in complete obstruction with suspected bowel ischaemia. • Role of CT enteroclysis in the diagnosis and management of small bowel obstruction is being evaluated. 17

SINGLE CONTRAST RETROGRADE ENEMA • Useful investigation in the management of patients with apparent large bowel obstruction. 18 • 96% sensitivity of and 98% specificity in diagnosing large bowel obstruction. 6 • Delineates the level of large bowel obstruction and distinguishes distal small bowel from colonic obstruction. 18 • In some patients in whom an acute distal small bowel obstruction is suspected on plain abdominal films, or whom the level of obstruction is indeterminate, it is appropriate to perform a single contrast retrograde enema to exclude a caecal lesion. • Dilute barium or water soluble iodinated contrast is used. If surgery is imminent, water-soluble contrast is preferred. • Advantages: quick, simple test undertaken without bowel preparation.

165 REFERENCES 1. Maglinte DDT, Reyes BL, Harmon BH, et al. Reliability and role of plain film radiography and CT in the diagnosis of small bowel obstruction. AJR 1996; 167: 1451-1455. (Retrospective study cohort of 78 patients – Level III evidence) 2. Macari M, Megibow A. Imaging of suspected acute small bowel obstruction. Seminars in Roentgenology 2001; 36(2): 108-117. 3. Peck JJ, Milleson T, Phelan J. The role of computed tomography with contrast and small bowel follow-through in management of small bowel obstruction. Am J Surg 1999; 177: 375-378. (Retrospective study cohort of 55 patients – Level III evidence) 4. Burkill GJC, Bell JRG, Healy JC. The utility of computed tomography in acute small bowel obstruction. Clinical Radiology 2001; 56: 350-359. 5. Shrake PD, Rex DK, Lappas JC, et al. Radiographic evaluation of suspected small bowel obstruction. Am J Gastroenterol 1991; 86: 175-178. (Retrospective study 117 consecutive patients – Level III evidence) 6. Chapman AH, McNamara M, Porter G. The acute contrast enema in suspected large bowel obstruction: value and technique. Clinical Radiology 1992; 46: 273-278. (Cohort of 140 patients – Level III evidence) 7. Grunshaw ND, Renwick IGH, Scarisbrick G, et al. Prospective evaluation of ultrasound in distal ileal and colonic obstruction. Clinical Radiology 2000; 55: 356- 362. (Prospective study 60 consecutive patients – Level II evidence) 8. Taourel PG, Fabre JM, Pradel JA, et al. Value of CT in the diagnosis and management of patients with suspected acute small-bowel obstruction. AJR 1995; 165: 1187-1192. (Cohort of 57 non-consecutive patients – Level III evidence) 9. Maglinte DDT, Gage S, Harmon B, et al. Obstruction of the : accuracy and role of CT in diagnosis. Radiology 1993; 188: 61-64. (Retrospective study cohort of 55 patients – Level III evidence) 10. Megibow AJ, Balthazar EJ, Cho KC, et al. Bowel obstruction: evaluation with CT. Radiology 1991; 180: 313-318. (Retrospective study cohort of 84 patients – Level III evidence) 11. Frager D, Baer JW, Medwid SW, et al. Detection of intestinal ischaemia in patients with acute bowel obstruction due to adhesions or hernia: efficacy of CT. AJR 1996; 166: 67-71. (Prospective study 60 patients – Level II/III evidence) 12. Balthazar EJ, Liebeskind ME, Macari M. Intestinal ischaemia in patients in whom small bowel obstruction is suspected: evaluation of accuracy, limitations, and clinical implications of CT in diagnosis. Radiology 1997; 205: 519-522. (Prospective study 100 consecutive patients – Level II evidence) 13. Zalcman M, Sy M, Donckier V, et al. Helical CT signs in the diagnosis of intestinal ischaemia in small-bowel obstruction. AJR 2000; 175: 1601-1607. (Prospective study 142 patients – Level II evidence) 14. Fink M, Freeman AH, Dixon AK, et al. Computed tomography of the colon in elderly people. BMJ 1994; 308: 1018. (Cohort of 66 elderly patients - Level III evidence) 15. Ko GY, Ha HK, Lee HJ, et al. Usefulness of CT in patients with ischaemic colitis proximal to colonic cancer. AJR 1997; 168: 951-956. (Retrospective study 20 case controls – Level IV evidence) 16. Walsh DW, Bender GN, Timmons JH. Comparison of computed tomography: enteroclysis and traditional computed tomography in the setting of suspected partial small bowel obstruction. Emerg Radiol 1998; 5: 29-37. 17. Bender GN, Maglinte DDT, Kloppel VR, et al. CT enteroclysis: is it another superfluous diagnostic procedure or does it have a role in the investigation of small bowel disease? AJR 1999; 172: 373-378.

166 18. Stewart J, Finan PJ, Courtney DF et al. Does a water soluble contrast enema assist in the management of acute large bowel obstruction: a prospective study of 117 cases. BJS 1984; 71: 799-801. (Prospective study 117 patients – Level II evidence)

Further Reading 1. Maglinte DDT, Kelvin FM, Rowe MG, et al. Small-bowel obstruction: optimizing radiologic investigation and nonsurgical management. Radiology 2001; 218: 39-46. (Review) 2. Maglinte DDT, Balthazar EJ, Kelvin FM, et al. The role of radiology in the diagnosis of small-bowel obstruction. AJR 1997; 168:1171-1180.

167 SUSPECTED INTRA-ABDOMINAL ABSCESS

ULTRASOUND • Initial imaging investigation of choice in the diagnosis of intra-abdominal abscess. 1- 3 • 85-95% diagnostic accuracy for detection and localisation of intra-abdominal abscess. 4-6 • Advantages: rapid, non-invasive, readily available and portable (preferred initial method in ICU patients). • Limitations: not suitable in obese patients and post-operative patients with surgical dressings, large wounds and/or ileus. 3

COMPUTED TOMOGRAPHY • “Gold standard” for the diagnosis of intra-abdominal abscess (superior diagnostic accuracy compared to ultrasound and nuclear medicine scan). 6-9 • Initial imaging study of choice in the post-operative patients. 7, 10 • Water-soluble contrast may be given orally or rectally to determine whether there is an ongoing leak at the anastomosis in patients who have undergone a bowel anastomosis. • In non-operative patients, CT is indicated if ultrasound is negative or inconclusive, and there is a high clinical suspicion of abscess. 11 • Advantages: provides high anatomical resolution, allows visualisation of retroperitoneal structures and intraluminal fluid collections. 9 • Disadvantages: requires patient transportation to radiology department. 168 NUCLEAR MEDICINE SCAN • Useful in detection of intra-abdominal abscess when there are no localised signs and in cases of occult sepsis or fever of unknown origin. 2, 12 • Gallium or white cell labelled scan may be performed, when a satisfactory CT and/or US scan have yielded negative results but early infection cannot be excluded. 2, 12-14 • Advantages: Allows detection of sites of infection beyond the abdominal region and can help distinguish normal post-operative inflammation from infection. • Disadvantages: long waiting period to allow appropriate concentration of isotope.

IMAGE GUIDED ASPIRATION/DRAINAGE • If an abscess is detected, CT- or US- guided percutaneous drainage, may be performed in the following: 15, 16 • All simple abscesses with safe drainage route. • Most complex abscesses with safe drainage route. • Pyogenic liver abscesses (single or few in number). • Infected pancreatic pseudocysts. 17-19 • Amoebic abscess (Although usually not necessary, can be drained. Most amoebic abscesses resolve on medical treatment and do not require percutaneous drainage unless causing symptoms related to large size.) • Abscesses not suitable for percutaneous drainage include: 15, 16 • Hydatid liver abscesses (usually secondarily infected hydatid cyst) • Multiple small liver abscesses. • Hepatic or other deeply situated abscesses in the presence of coagulopathy and/or ascites. • Uncertain role of percutaneous drainage in: • Pancreatic and splenic abscesses • Infected necrotic tumours. • There are no prospective randomised controlled trials to support above recommendations. These recommendations are mainly based on retrospective studies (level III evidence).

WATER SOLUBLE CONTRAST STUDY • In post-operative patients who have undergone a bowel anastomosis, a water soluble contrast study (per oral or enema) may be indicated to determine whether there is any anastomotic leak, but is perhaps better given in conjunction with CT.

169 REFERENCES 1. Kochel JQ, Koehler PR, Lee TG, et al. Diagnosis of abdominal abscesses with computed tomography, ultrasound, and 111-In leuckocyte scans. Radiology 1980; 137: 425-432. (Retrospective study cohort 170 patients – Level II/III evidence) 2. Carter CR, McKillop JH, Gray HW, et al. Indium-111 leucocyte scintigraphy and ultrasound in the detection of intra-abdominal abscesses in patients without localizing signs. J R Coll Surg Edinb 1995; 40: 380-382. (Retrospective study cohort of 45 patients – Level II/III evidence) 3. Weldon MJ, Joseph AE, French A, et al. Comparison of 99m-technetium hexamethylpropylene-amine oxime labelled leucocyte with 111-indium tropolonate labelled granulocyte scanning and ultrasound in the diagnosis of intra-abdominal abscess. Gut 1995; 37: 557-564. (Prospective 50 nonconsecutive patients – Level III evidence) 4. Taylor KJW, Wasson JF, De Graff C, et al. Accuracy of grey scale ultrasound diagnosis of abdominal and pelvic abscesses in 220 patients. Lancet 1978; 1: 83-84. (Retrospective Study 220 patients – Level II/III evidence) 5. Korobkin M, Callen PW, Filly RA, et al. Comparison of computed tomography, ultrasonography, and gallium-67- scanning in the evaluation of suspected abdominal abscess. Radiology 1978; 129: 89-93. (Retrospective study 29 consecutive patients – Level III evidence) 6. Dobrin PB, Gully PH, Greenlee HB, etal. Radiologic diagnosis of an intra- abdominal abscess. Do multiple tests help? Arch Surg 1986; 10: 111-114. (Retrospective study cohort of 94 patients - Level III evidence) 7. Lundstedt C, Hederstrom E, Brismar J, et al. Prospective investigation of radiologic methods in the diagnosis of intra-abdominal abscesses. Acta Radiol Diagn 1986; 27: 49-54. (Prospective study 40 patients – Level II/III evidence) 8. Roche J. Effectiveness of computed tomography in the diagnosis of intra-abdominal abscess: a review of 111 patients. MJA 1981; 2: 85-88. (Prospective study 111 patients – Level II/III evidence) 9. Gazelle GS, Mueller PR. Abdominal abscess: imaging and intervention. Radiologic Clinics of North America 1994; 32(5): 913-933. 10. Bearcroft PW, Miles KA. Leucocyte scintigraphy or computed tomography for the febrile post-operative patients? European J Radiology 1996; 23: 126-129. (Retrospective study 67 consecutive patients – Level II/III evidence) 11. Paling MR, Gouse JC. Efficacy of abdominal computed tomography in evaluation of possible abdominal abscess. CT: Journal of Computed Tomography 1986; 10: 111-114. (Retrospective study 130 patients – Level III evidence) 12. Baldwin JE, Wraight EP. Indium labelled leucocyte scintigraphy in occult infection: comparison with ultrasound and computed tomography. Clinical Radiology 1990; 42: 199-202. (Retrospective study – Level III evidence) 13. Tsai SC, Chai TH, Lin WY, et al. Abdominal abscesses in patients having surgery: an application of Ga-67 scintigraphic and computed tomographic scanning. Clinical Nuclear Medicine 2001; 26(9): 761-764. (Prospective 34 post-op patients – Level III evidence) 14. Goldman M, Ambrose NS, Drolc Z, et al. Indium-111-labelled leucocytes in the diagnosis of abdominal abscess. Br J Surg 1987; 74: 184-186. (Prospective study 100 consecutive patients – Level II evidence). 15. VanSonnenberg E, Wittich GR, Goodcare BW, et al. Percutaneous abscess drainage: update. World J Surg 2001; 25: 362-372. 16. ACR appropriateness criteria. Percutaneous catheter drainage of infected intra- abdominal fluid collections. American college of Radiology, Reston, 1996.

170 17. Mithofer K, Mueller PK, Warshaw Al. Interventional and surgical treatment of pancreatic abscess. World J Surg 1997; 21: 162. 18. VanSonnenberg E, Wittich GR, Casola G, et al. Percutaneous drainage of infected and non infected pancreatic pseudocysts: experience in 101 cases. Radiology 1989; 170: 757. 19. VanSonnenberg E, Wittich GR, Chon KS, et al. Percutaneous radiologic drainage of pancreatic abscesses. AJR 1997; 168: 979.

171 ACUTE OR ACUTE ON CHRONIC RENAL FAILURE

DOPPLER ULTRASOUND • Modality of choice for renal imaging. 1,2 • Routine use is not indicated. 2,3 • Provides morphological and functional information useful for the diagnosis and management of specific pathological conditions leading to acute renal failure. 1,2 • Helps differentiate potentially reversible acute renal failure from chronic end-stage renal disease. 1,2 • Allows detection of obstruction, assessment of renal size and outline. 4 • Renal size is usually normal in prerenal acute renal failure and it may increase in acute renal diseases such as acute tubular necrosis, interstitial nephritis and acute glomerular nephritis. Reduced size suggests a complicated underlying chronic nephropathy and worse prognosis. 1 • Doppler ultrasound can be used to distinguish renal obstruction from non- obstructive dilatation. RI of 0.7 or less in the presence of dilatation of collecting system is supportive evidence of absence of functionally significant obstruction. 4-6 • Limitations: 1,2 • Poor specificity. • False negatives may occur in early renal obstruction and in dehydrated patients.

172 RADIONUCLIDE RENAL SCAN • Renal perfusion, filtration and excretion can be evaluated which are helpful in determining the potential for salvage. 7-9 • There are no comprehensive series describing DTPA or MAG3 renography in patients with acute renal failure and no evidence that serial renography contributes more to patient management than does the measurement of urine volume and creatinine content. 9

ANGIOGRAPHY • Catheter or CT angiography involves the use of iodinated contrast medium, which is usually contraindicated in acute renal failure. MR angiography is a useful alternative in these circumstances.

RENAL BIOPSY • When the cause of declining renal function is not found and the clinical features are atypical of acute tubular necrosis, renal biopsy may be used to exclude potentially treatable conditions such as Wegener’s granulomatosis, systemic lupus erythematosus, Goodpasture’s syndrome or rapidly progressive glomerulonephritis.

ANTEGRADE PYELOGRAPHY • Used to assess the underlying cause and level of obstruction when hydronephrosis is diagnosed with US. • Percutaneous nephrostomy can be performed at the same time as a temporary means of urinary diversion.

173 REFERENCES 1. Mucelli RP, Bertolotto M. Imaging techniques in acute renal failure. Kidney Int 1998; 53 (S66): S102-S105. 2. O’Neill WC. Sonographic evaluation of renal failure. Am J Kidney Diseases 2000; 35(6): 1021-1038. 3. Gottlieb RH, Weinberg EP, Rubens DJ, et al. Renal sonography: can it be used more selectively in the setting of an elevated serum creatinine level? Am J Kidney Dis 1997; 29: 362-367. (Retrospective study cohort of 60 patients – Level III evidence) 4. Platt JF. Advances in ultrasonography of urinary tract obstruction. Abdom Imaging 1998; 23: 3-9. 5. Platt JF. Doppler ultrasound of the kidney. Semin Ultrasound CT MRI 1997; 18: 22- 32. 6. Platt JF. Duplex doppler evaluation of native kidney dysfunction: obstructive and nonobstructive disease. AJR 1992; 158: 1035-1042. 7. Fresco GF, DiGiorgio F, Curti GL. Simultaneous estimation of glomerular filtration rate and renal plasma flow. J Nucl Med 1995; 36(9): 1701-1706. 8. Blaustein DA, Myint MM, Babu K, et al. The role of technetium-99m MAG3 renal imaging in the diagnosis of acute tubular necrosis of native kidneys. Clin Nucl Med 2002; 27: 165-168. (Case studies – Level IV evidence) 9. Woolfson RG, Neild GH. The true clinical significance of renography in nephro- urology. European J Nucl Med 1997; 24(5): 557-570. (Review)

174 ACUTE RENAL TRANSPLANT DYSFUNCTION

DOPPLER ULTRASOUND • Indicated in almost all patients with allograft dysfunction or urinary tract abnormalities. 1,2 • Sensitivity approaching 100% in diagnosing urinary tract obstruction, a common cause of acute allograft failure. 3 • US findings in acute renal transplant dysfunction include swelling, enlarged pyramids, decreased cortico-medullary differentiation and Doppler changes such as increased resistive index. However these findings are non-specific and can be seen in acute tubular necrosis and cyclosporin toxicity. 2,4 • In the immediate postoperative period, sonography is useful in diagnosing such surgical causes of delayed graft function as thrombosis of the renal artery or vein, urinary obstruction caused by ureteral kinks, and urine leaks. 1,3 • Colour and power Doppler provide useful information regarding blood flow to the kidney and vascular complications in renal allografts. 5-9 • In occlusion of the main renal artery by thrombus, Doppler US demonstrates a lack of arterial flow distal to the occlusion and absence of venous flow. 1,2,7,8 • Renal vein thrombosis presents marked elevated resistive index and reverse arterial flow in diastole together with absent venous signals. 1,2 • Useful for: 1 • Guiding percutaneous biopsy. • Diagnosing fluid collections in patients with graft pain or ipsilateral leg oedema. • Measurement of residual bladder volume. • Identification of ureteral stents. • Limitations: lacks specificity (false positives for urinary tract obstruction may result, if collecting system of kidney is not examined when bladder is empty, since full bladder may cause dilatation of transplant collecting system). 4

175

RADIONUCLIDE IMAGING • Allows assessment of graft perfusion, function and excretion. The most common finding is normal perfusion with increased retention and little excretion indicating acute tubular necrosis. Acute rejection impairs perfusion and function. 10 • Useful in the diagnosis of obstruction and cortical scar formation in the renal transplant but its contribution to the diagnosis of parenchymal dysfunction remains unproven. 10

RENAL ANGIOGRAM • Useful in confirming and possibly treating stenoses in patients with positive US or those with inadequate or equivocal US when clinical suspicion is strong. 1,7,8

RENAL BIOPSY • “Gold Standard” in the diagnosis of acute renal transplant rejection. 1,4,9 • Disadvantages: invasive procedure with a risk of complications. 11

176 REFERENCES 1. O’Neill WC, Baumgarten DA. Ultrasonography in renal transplantation. American Journal of Kidney Diseases 2002; 39(4): 663-678. 2. Tublin ME, Dodd GD III. Sonography of renal transplantation. Radiol Clin North America 1995; 33: 447-459. 3. Gottlieb Th, Voci SL, Cholewinski SP, et al. Sonography: a useful tool to detect the mechanical causes of renal transplant dysfunction. J Clin Ultrasound 1999; 27: 325- 333. (Retrospective study 63 consecutive patients – Level II/III evidence) 4. Kelcz F, Pozniak MA, Pirsch JD, et al. Pyramidal appearance and resistive index: insensitive and nonspecific sonographic indicators of renal transplant rejection. AJR 1990; 155: 531-535. (Prospective study 89 consecutive patients – Level II evidence) 5. Turetschek K, Nasel C, Wunderbaldinger P, et al. Power Doppler versus Color Doppler imaging in renal allograft evaluation. J Ultrasound Med 1996; 15: 517-522. (Prospective study 72 consecutive renal allograft recipients – Level II evidence) 6. Claudon M, Lefevre F, Hestin D, et al. Power Doppler imaging: evaluation of vascular complications after renal transplantation. AJR 1999; 173: 41-46. 7. Grenier N, Douws C, Morel D, et al. Detection of vascular complications in renal allografts with color Doppler flow imaging. Radiology 1991; 178: 217-223. (Cohort of 146 renal allografts – Level III evidence) 8. Taylor KJW, Morse SS, Rigsby CM, et al. Vascular complications in renal allografts: detection with duplex Doppler US. Radiology 1987: 162: 31-38. (Cohort of 88 renal allografts – Level III evidence) 9. Sidhu MK, Gambhir S, Jeffery RB Jr, et al. Power Doppler imaging of acute renal transplant rejection. J Clin Ultrasound 1999; 27: 171-175. (Retrospective study cohort of 28 patients referred for renal biopsy – Level III evidence) 10. Woolfson RG, Neild GH. The true clinical significance of renography in nephro- urology. European J Nucl Med 1997; 24(5): 557-570. (Review) 11. Wilczek HE. Percutaneous needle biopsy of the renal allograft. Transplantation 1990; 50: 790-797. (Retrospective study 1129 biopsy specimens – Level III evidence)

Further Reading 1. Baxter GM. Ultrasound of renal transplantation. Clinical Radiology 2001; 56: 802- 818. (Pictorial Review)

177 LOWER URINARY TRACT SYMPTOMS

LOWER URINARY TRACT SYMPTOMS (LUTS) • Lower urinary tract symptoms (LUTS) is the complex of obstructive and irritative urinary symptoms. 1 • Symptoms include urinary hesitancy, poor “stream”, straining, frequency, incomplete bladder emptying, urgency, terminal urinary dribbling, and nocturia. 1 • LUTS may be caused by a variety of factors including changes in the bladder, prostate, urethra or upper urinary tract. Common causes include urinary tract infection, benign prostatic hypertrophy, urethral stricture, neurogenic bladder, bladder neck , prostate and bladder cancer. 1 • Management of patients with LUTS is based on making a diagnosis and subjective measurements of symptom severity and bother. 1

ULTRASOUND • Transabdominal ultrasound is indicated in all patients with LUTS and renal insufficiency. 1, 2 • Allows: • Assessment of upper tract changes such as hydronephrosis. • Determination of post-void residual. 3 • Superior to IVP in detecting secondary changes of the bladder outlet obstruction such as bladder wall thickening. 4 • Advantages: non-invasive, no ionising radiation and does not require the use of contrast agent.

178 INTRAVENOUS (IVP) • Routine use is not indicated in all patients with symptoms of lower urinary tract symptoms. 1, 5, 6 • Indicated in patients with other associated findings such as: 1, 2 • Stones on plain films • Haematuria • Atypical history • Imaging of upper urinary tract with IVP allows: 1 • Determination of the presence, degree and cause of upper urinary tract obstruction (hydronephrosis). • Estimation of renal function. • Evaluation of bladder. • Detection of incidental upper tract (renal or ureteral) malignancies or stones. • Limitations: less sensitive for evaluation of lower urinary tract. • Disadvantages: requires the use of contrast agent and involves exposure to ionising radiation.

179 REFERENCES 1. Grossfield GD, Coakley FV. Benign prostatic hyperplasia: clinical overview and value of diagnostic imaging. Radiologic Clinics of North America 2000; 38(1): 31- 47. 2. Scheckowitz EM, Resnick MI. Imaging of the prostate: benign prostatic hyperplasia. Urologic Clinics of North America 1995; 22(2): 321-332. 3. Roehrborn CG, Chinn HK, Fulgham PF, et al. The role of transabdominal ultrasound in the evaluation of patients with benign prostatic hypertrophy. J Urol 1986; 135(6): 1190-1193. (Prospective study 59 consecutive patients – Level II evidence) 4. Cascione CJ, Bartone FF, Hussain MB. Transbdominal ultrasound versus excretory urography in preoperative evaluation of patients with prostatism. J Urol 1987; 137(5): 883-885. (Prospective study 53 patients – Level II/III evidence) 5. Wasserman NF, Lapointe S, Eckmann DR, et al. Assessment of prostatism: role of intravenous urography. Radiology 1987; 165(3): 831-835. (Prospective study 502 patients – Level II/III evidence) 6. De Lacy G, Johnson S, Mee D. Prostatism: how useful is routine imaging of the urinary tract? Br Med J 1988; 296(6627): 965-967. (Prospective study 128 consecutive patients – Level II evidence)

180 PAINLESS HAEMATURIA – NON-GLOMERULAR ORIGIN

CLINICAL ASSESSEMENT • Clinical assessment, urine culture and appropriate screening laboratory tests can help exclude benign causes (vigorous exercise, infection, viral illness, sexual activity, and menstruation) and in such patients routine imaging with US or IVP is not indicated. 1-4 • Imaging can be used to detect renal cell carcinoma, transitional cell carcinoma in the pelvicalyceal system or ureter, urolithiasis and renal infection. 1 • There is no universal agreement with regard to the first imaging examination to choose for investigation of haematuria. Clinical assessment can help direct the investigation pathway. 1-4 • Both IVP and Ultrasound have moderately high sensitivity in detecting the abnormalities but they tend to miss different types of lesions. So combination of IVP and ultrasound is often used in the initial investigation of asymptomatic haematuria. 5, 6

INTRAVENOUS PYELOGRAM (IVP) • Traditionally, has been initial investigation of choice for evaluation of upper tract imaging. 2-4 • Described as best “catch all” method for the upper urinary tract. 2 • Allows functional and anatomical assessment of upper and to a lesser extent lower urinary tract. • Superior to US for detection of stone disease. 7 • Limitations: • Limited sensitivity in detecting small renal masses (may miss small exophytic anterior and posterior renal masses). 8

181 • Inability to distinguish solid from cystic masses. Therefore, when a mass is identified on IVP, further lesion characterisation by US +/- CT is indicated. 8, 9 (See renal mass algorithm) • Advantages: • Widely available. • Relatively inexpensive. • Disadvantages: • Ionising radiation. • Potential complications due to contrast media.

ULTRASOUND • Investigation of choice for investigating renal parenchyma and excluding significant upper urinary tract obstruction. 4 • Increasingly being employed as initial imaging modality in the evaluation of haematuria. 10 • Superior to IVP in: • Detection and characterisation of renal masses. 8 • Detection of bladder tumours. 5, 9, 10 • Limitations: • Reduced sensitivity for detection of small solid lesions less than 3cm in size. 11 • Can miss non-obstructing ureteral stones and small urothelial abnormalities. 12, 13 • Advantages: • Safer than IVP (no ionising radiation or use of contrast agent). • Less expensive.

RETROGRADE PYELOGRAM • Best imaging approach for the detection and characterisation of ureteral abnormalities. • Used when the collecting system is not adequately demonstrated by US or IVP. 3

CYSTOSCOPY • “Gold standard” for detection of bladder cancer. 14 • Indicated in all patients with macroscopic haematuria. 15 • Recommended for evaluation of asymptomatic microscopic haematuria in all adult patients older than 40 years and for those younger than 40 years with risk factors for the development of bladder cancer such as smoking history, occupational chemical exposure, or a history of irritative voiding symptoms. 1 • Low yield (<1%) in “low risk” patients with asymptomatic microscopic haematuria. Therefore, cystoscopy may be deferred in this group. 1, 6, 16 • Follow up is indicated in patients with a negative initial evaluation of asymptomatic haematuria as some of these patients eventually develop significant urological disease. 1, 5, 6 • Advantages: provides direct visualisation of the bladder mucosa and allows washings and biopsies of suspicious lesions to be performed. 1

COMPUTED TOMOGRAPHY • Best imaging modality for: • Detection and characterisation of solid renal masses. 8 • Evaluation of urinary stones, renal and perirenal infections, and associated complications. 7

182 • Can detect small renal masses undetectable on US and may be used to evaluate the renal tract in cases where US is unsatisfactory. 8 • A recently published study supports the use for CT for investigation of haematuria of undetermined cause. 17

183 REFERENCES 1. Grossfield GD, Litwin MS, Wolf Jr S, et al. Evaluation of asymptomatic microscopic hematuria in adults: the American Urological Association best practice policy - Parts I and II. Urology 2001; 57(4): 599-603 & 604-610. 2. Webb JAW. Imaging in haematuria in adults. Clinical Radiology 1997; 52: 167-171. (Editorial) 3. Sutton JM. Evaluation of haematuria. JAMA 1990; 263(18): 2475-2480. (Review) 4. Rockall AG, Newman-Sanders APG, Al-Kutoubi MA, et al. Haematuria. Postgraduate Med J 1997; 73: 129-136. 5. Khadra MH, Pickard RS, Charlton M, et al. A prospective analysis of 1,930 patients with hematuria to evaluate current diagnostic practice. J Urol 2000; 163: 524-527. (Prospective study 1,930 patients – Level II evidence) 6. Murakami S, Igarashi T, Hara S, et al. Strategies for asymptomatic haematuria: a prospective study of 1034 patients. J Urol 1990; 144: 99-101. (Prospective study 1034 patients – Level II evidence) 7. Yilmaz S, Sindel T, Arslan G, et al. Renal colic: comparison of spiral CT, US and IVU in the detection of ureteral calculi. Eur Radiol 1998; 8: 212-217. (Prospective study 97 patients – Level II/III evidence) 8. Warshauer DM, McCarthy SM, Street L, et al. Detection of renal masses: sensitivities and specificities of excretory urography/linear tomography, US and CT. Radiology 1988; 169: 363-365. (Prospective blinded study of 201 patients – Level II evidence) 9. Spencer J, Lindsell D, Mastorakou I. Ultrasonography compared with intravenous urography in the investigation of adults with haematuria. Br Med J 1990; 301: 1074-1076. (Prospective study 155 consecutive patients – Level II evidence) 10. Yip SKH, Peh WCG, Tam PC, et al. Role of ultrasonography in screening for urological malignancies in patients presenting with painless haematuria. Ann Acad Med Singapore 1999; 28(2): 174-177. (Prospective study 468 consecutive patients – Level II evidence) 11. Jamis-Dow CA, Choyke PL, Jennings SB, et al. Small (≤ 3-cm) renal masses: detection with CT versus US and pathologic correlation. Radiology 1996; 198:785-788. (Prospective study 21 patients with 205 renal masses – Level II/III evidence) 12. Aslaken A, Gadeholt G, Gothlin JH, et al. Ultrasonography versus intravenous urography in the evaluation of patients with microscopic haematuria. Br J Urol 1990; 66: 144-147. (Prospective study 193 patients – Level II evidence) 13. Fowler KAB, Locken JA, Duchesne JH, et al. US for detecting renal calculi with nonenhanced CT as a reference standard. Radiology 2002; 222:109-113. (Retrospective study cohort of 123 patients – Level III evidence) 14. Grossfield GD, Carroll PR. Evaluation of asymptomatic microscopic haematuria. Urologic Clinics of North America 1998; 25: 661-676. (Review) 15. Buntinx F, Wauters H. The diagnostic value of macroscopic haematuria in diagnosing urological cancer: a meta-analysis. Fam Pract 1997; 14: 63-68. (Meta- analysis – Level II/III evidence) 16. Sultana SR, Goodman CM, Byrne DJ, et al. Microscopic haematuria: urological investigation using a standard protocol. Br J Urol 1996; 78: 691-698. (Prospective audit of 381 patients with microscopic haematuria – Level II evidence) 17. Lang EK, Macchia RJ, Thomas R, et al. Computerized tomography tailored for the assessment of microscopic hematuria. J Urol 2002; 167: 547-554. (Prospective multicenter trial 350 consecutive patients – Level II evidence)

184 ACUTE FLANK PAIN/RENAL COLIC

IMAGING IN ACUTE RENAL COLIC • Diagnosis of renal colic can be suspected on clinical history and examination, but diagnostic imaging is essential to confirm the diagnosis. 1 • Investigation of choice is intravenous pyelogram (IVP) or non-enhanced spiral CT scan (NECT). • Non-enhanced CT is more accurate and is able to establish alternative diagnoses in some patients. 3 However, in patients with typical symptoms of renal colic outcome may not differ whether IVP or NECT is used. • In addition, NECT (at current standard protocols) is associated with significantly greater radiation dose. Currently, low dose protocols for NECT are under investigation, if accuracy is preserved into these protocols then NECT will become the best choice in most patients. • Plain films (KUB) is used to assess stone radio-opacity and as baseline for follow up.

PLAIN RADIOGRAPHS (KUB) • Sensitivity 45-59% and specificity 64-77% for detecting ureteral calculi. 2-5 • May be sufficient to document the size and location of radio-opaque urinary calculi (calcium oxalate or phosphate stones). 1 • Useful initial investigation in patients with known stone disease and follow up of patients with known radio-opaque calculi. 1 • Advantages: accessible and inexpensive • Limitations: stones in middle section of ureter, phleboliths, radiolucent calculi (uric acid stones), extra-urinary calcifications and non-genitourinary conditions. 1

185 INTRAVENOUS PYELOGRAM (IVP) • Traditionally, IVP has been the investigation of choice for suspected renal colic. 1 • Superior to US and KUB in detection of ureteral calculi (sensitivity 64-87% and specificity 92-94%). 3, 6, 7 • Advantages: 1 • Provides precise information regarding site and degree of obstruction, size of stone, and the effect of obstruction on renal function. • Lower radiation dose, less expensive and more readily available compared to Spiral CT. 8, 9 • Disadvantages: 1 • Variable quality imaging. • Potential risk of allergy or nephrotoxicity due to use of contrast media. • Poor visualisation of non-genitourinary conditions. • Delayed images required in high-grade obstruction.

NON-ENHANCED COMPUTED TOMOGRAPHY (NECT) • Imaging investigation of choice for suspected renal colic at an increasing number of institutions and practices. 9-11 • Superior to US and IVP for detection and determination of the exact size and location of ureteral calculi and guiding the appropriate management (94-100% sensitivity and 93-98% specificity for ureteral calculi). 3, 6-8, 12, 13 • Advantages: • Facilitates fast, definitive diagnosis. 14, 15 • Well tolerated. • Can demonstrate non-stone related urinary causes (eg pyelonephritis) and extra urinary causes of acute flank pain (eg appendicitis) or ureteric obstruction. 16 • Recent study suggested the use of ureteral calculi size and CT attenuation values >300H to predict cases in which abdominal radiographs are likely to reveal ureteral calculi and hence plain radiograph for follow-up in these cases. 17 • Disadvantages: 1, 6 • Higher radiation dose than IVP. 8, 9 • No direct measure of renal function. • Less accessible. • Relatively expensive (A recently published New Zealand randomized study has reported broadly comparable imaging costs of Spiral CT to IVP). 9

ULTRASOUND • Preferred examination in pregnant patients. • >90% sensitivity and specificity for detection of urinary tract obstruction in patients with renal colic. 18 • Low sensitivity (10-50%) but high specificity (90%) for ureteral stones. 6, 19 • Improved accuracy in combination with plain radiographs. 20 • Advantages: 1 • Useful in assessing renal parenchymal processes, which may mimic renal colic. • High sensitivity in detecting other conditions such as cholelithiasis, acute pancreatitis, acute appendicitis and abdomino-pelvic masses that may mimic the pain of renal colic. • Lacks exposure to ionising radiation. • Readily available. • Relatively inexpensive.

186 • Limitations: 1 • Inability to depict entire length of the ureters. • Poor visualisation of ureteral stones. 6, 19 • Inability to determine the level and cause of obstruction.

187 REFERENCES 1. Portis AJ, Sundraram CP. Diagnosis and initial management of kidney stones. American Family Physician 2001; 63: 1329-1338. 2. Levine JA, Neitlich J, Verga M, et al. Ureteral calculi in patients with flank pain: correlation of plain radiography with unenhanced helical CT. Radiology 1997; 204: 27-31. (Retrospective study 178 patients – Level III/IV evidence) 3. Niall O, Russell J, MacGregor R, et al. A comparison of noncontrast computerized tomography with excretory urography in the assessment of acute flank pain. J Urol 1999; 161:534-537. (Prospective study 40 consecutive patients – Level II/III evidence) 4. Mutgi A, WilliamsJW, Nettleman M. Renal colic utility of the plain abdominal roentgenogram. Arch Intern Med.1991; 151(8): 1589 -1592. (Retrospective cohort study of 85 consecutive patients– Level III evidence) 5. Assi Z, Platt JF, Francis IR, et al. Sensitivity of CT scout radiography and abdominal radiography for revealing ureteral calculi on helical CT: implications for radiologic follow up. AJR 2000; 175: 333-337. (Retrospective study cohort of 60 patients with ureteral calculi on helical CT- Level III evidence) 6. Yilmaz S, Sindel T,Arslan G, et al. Renal colic: comparison of spiral CT, US and IVU in the detection of ureteral calculi. Eur Radiol 1998; 8: 212-217. (Prospective study 97 patients – Level II/III evidence) 7. Miller OF, Rineer SK, Reichard SR, et al. Prospective comparison of unenhanced spiral computed tomography and intravenous urogram in the evaluation of acute flank pain. Urology 1998; 52: 982-987. (Prospective study 106 patients – Level II/III evidence) 8. Homer JA, Davies-Payne DL, Peddinti BS. Randomized prospective comparison of non-contrast enhanced helical computed tomography and intravenous urography in the diagnosis of acute ureteric colic. Australasian Radiology 2001; 45:285-290. (Prospective randomised study 228 patients – Level II evidence) 9. Thomson JMZ, Glocer J, Abbott C, et al. Computed tomography in diagnosis of acute flank pain from urolithiasis: a randomized study comparing imaging costs and radiation dose. Australasian Radiology 2001; 45:291-297. (Prospective randomised study 224 consecutive patients - Level II evidence) 10. Vieweg J, The C, Freed K, Leder RA, Smith RHA, Nelson RH, Preminger GM. Unenhanced helical computerized tomography for the evaluation of patients with acute flank pain. J Urol 1998; 160:679-684. (Prospective study 105 consecutive patients – Level II evidence) 11. Greenwell TJ, Woodhams S, Denton ER, et al. One year’s clinical experience with unenhanced spiral computed tomography for the assessment of acute loin pain suggestive of renal colic. BJU Int 2000; 85(6): 632-636. (Prospective study 116 patients – Level II/III evidence) 12. Smith R, Verga M, McCarthy S, Rosenfield AT. Diagnosis of acute flank pain: value of unenhanced helical CT. AJR 1996; 166:97-101. (Prospective study 292 patients – Level II/III evidence) 13. Fowler KAB, Locken JA, Duchesne JH, et al. US for detecting renal calculi with nonenhanced CT as a reference standard. Radiology 2002; 222:109-113. (Retrospective study cohort of 123 patients – Level III evidence) 14. Patel M, Han SSY, Vaux K, et al. A protocol of early spiral computed tomography for the detection of stones in patients with renal colic has reduced the time to diagnosis and overall management cost. Aust NZ J Surg 2000; 70: 39-42. (Retrospective study 200 patients – Level III/IV evidence) 15. Rekant EM, Gibert CL, Counselman FL. Emergency department time for evaluation of patients discharged with a diagnosis of renal colic: unenhanced helical computed

188 tomography versus intravenous urography. J Emerg Med 2001; 21(4): 371-374. (Retrospective study case control 98 consecutive patients - Level IV evidence) 16. Katz DS, Scheer MS, Lumeman JH, et al. Alternative of additional diagnoses on unenhanced helical CT for suspected renal colic: experience with 1000 consecutive patients. Urology 2000; 56: 53-57. (Retrospective study 1000 consecutive patients – Level II/III evidence) 17. Zagoria RJ, Khatod EG, Chen MYM, et al. Abdominal radiography after CT reveals urinary calculi: a method to predict usefulness of abdominal radiography on the basis of size and CT attenuation of calculi. AJR 2001; 176: 1117-1122. (Retrospective study 49 patients - Level III/IV evidence) 18. Shokier AA, Abdulmaaboud M. Prospective comparison of nonenhanced helical computerized tomography and Doppler ultrasonography for the diagnosis of renal colic. J Urol 2001; 165: 1082-1084. (Prospective study 109 patients – Level II/III evidence) 19. Patlas M, Farkas A, Fisher D, et al. Ultrasound vs CT for the detection of ureteric stones on patients with renal colic. Br J Radiol 2001; 74: 901-904. (Prospective study 62 consecutive patients – Level II evidence) 20. Haddad MC, Sharif HS, Shahed MS, et al. Renal colic: diagnosis and outcome. Radiology 1992; 184; 83-88. (Prospective study 101 consecutive patients with IVP as a standard of reference – Level II evidence)

Further Reading: 1. Smith RC, Levine J, Rosenfield AT. Helical CT of urinary tract stones. Epidemiology, origin, pathophysiology, diagnosis and management. Radiol Clin North America 1999; 37: 911-952, v. 2. Dall Palma L, Pozzi-Mucelli R, Stacul F. Present-day imaging of patients with renal colic. Eur Radiol 2001; 11: 4-17. 3. Grisi G, Stacul F, Cuttin R. Cost analysis of different protocols for imaging a patient with acute flank pain. Eur Radiology 2000; 10: 1620-1627.

189 RENAL MASS

ULTRASONOGRAPHY (US) • Initial imaging modality of choice for evaluation of renal mass. 1-3 • ~ 80% sensitivity for detection of renal parenchymal masses. 4 • Most cost-effective study for evaluation and characterisation of a benign cyst. 3 • US criteria for a simple benign cyst are: 2 1. Spherical or ovoid shape. 2. Anechoic. 3. Sharply defined back wall. 4. Enhancement of through sound transmission. • When the ultrasound criteria for a simple cyst are met, the likelihood of malignancy is extremely small. Hence asymptomatic patients with incidental renal cysts do not require additional evaluation. 1, 2 • Advantages: 3 • No exposure to ionising radiation. • Does not require use of contrast material. • Relatively inexpensive. • Limitations: less accurate than CT for revealing small renal masses. 5

190 INTRAVENOUS PYELOGRAM (IVP) • Moderate sensitivity (~67%) for detection of renal masses. 4 • Limitations: poorly characterises lesions as benign. 4 • Disadvantages: exposure to ionising radiation and use of contrast material with potential risk of complications.

COMPUTED TOMOGRAPHY (CT) • “Gold standard” for evaluation of renal masses. 1, 2 • >90% sensitivity for identifying small renal cell carcinomas. 6 • Superior to US for detection and characterisation of renal masses. 4, 5 • Used to clarify all the hypoechoic masses or complex cysts that do not fulfil the sonographic criteria for a simple cyst. 1 • Enables detection of small amounts of fat that identifies benign angiomyolipoma. 7 • Bosniak classification of cystic renal masses: 2, 8, 9 • Class I: simple benign cysts (round/oval, nonenhancing, unilocular) – require no further evaluation. • Class II: probable benign simple cystic lesions that are minimally complicated (one or two septa, minimally calcified cysts, hyperdense contents) – radiological surveillance at 6 or 12 months. • Class III: more complicated cystic lesions (some malignant features: thick, irregular borders, irregular calcifications, multilocular, thickened septa) – consider fine needle aspiration biopsy. • Class IV: clearly malignant cystic masses (thickened walls, heterogenous, shaggy, enhancing) – surgery. • Magnetic resonance imaging, with a comparable accuracy, is an alternative if CT cannot be performed because of contrast media reaction or renal insufficiency. 10, 11

NUCLEAR MEDICINE SCAN (DMSA) • Use limited to evaluation of “pseudotumours” caused by normal renal tissue eg column of Bertin, seen on IVP or US. 8

PERCUTANEOUS FINE NEEDLE ASPIRATION / BIOPSY (FNAC) • Imaging features of renal masses are more reliable for accurate diagnosis than are cytological or histological findings from needle biopsy specimens. 1 • Image guided biopsy is useful for: • Evaluation of “indeterminate” renal masses on imaging studies. 12, 13 • Confirmation of infected cyst or abscess. • Distinguishing solitary metastases from a primary renal lesion. 13, 14 • Limitations: 12, 13 • Significant rate (20-30%) of false negative and non-diagnostic results. Therefore, cannot be used to exclude malignancy. • Potential risks and complications include haemorrhage, pneumothorax and needle seeding.

191 REFERENCES 1. Zagoria RJ. Imaging of small renal masses: a medical success story. AJR 2000; 175: 945-955. 2. Higgins JC, Fitzgerald JM. Evaluation of incidental renal and adrenal masses. American Family Physician 2001; 63: 288-294. 3. Einstein DM, Hens BR, Weaver R, Obuchowski N, Zepp R, Singer A. Evaluation of renal masses detected by excretory urography: cost-effectiveness of sonography versus CT. AJR 1995;164:371-375. (Retrospective study 225 patients – Level II evidence) 4. Warshauer DM, McCarthy SM, Street L, et al. Detection of renal masses: sensitivities and specificities of excretory urography/linear tomography, US and CT. Radiology 1988; 169: 363-365. (Prospective blinded study 201 patients – Level II evidence) 5. Jamis-Dow CA, Choyke PL, Jennings SB, Linehan WM, Thakore KN, Walther MM. Small (< 3-cm) renal masses: detection with CT versus US and pathologic correlation. Radiology 1996; 198: 785-788. (Retrospective study 205 renal masses resected from 21 patients with von Hippel-Lindau disease or hereditary papillary renal cell carcinoma – Level II/III evidence) 6. Amendola MA, Bree RL, Pollack HM, et al. Small renal cell carcinomas: resolving a diagnostic dilemma. Radiology 1988; 166: 637-641. (Retrospective study 39 patients with renal cell carcinomas ≤3cm – Level IV evidence) 7. Bosniak MA, Megibow AJ, Hulnick DH, et al. CT diagnosis of renal angi- omyolipoma: the importance of detecting small amounts of fat. AJR 1988; 151: 497-501. (Retrospective study 6 patients with angiomyolipoma + 100 patients with renal cell carcinomas ≤4cm – Level IV evidence) 8. Bosniak M. The small (< 3.0 cm) renal parenchymal tumor: detection, diagnosis, and controversies. Radiology 1991; 179: 307-317. 9. Wolf JS. Evaluation and management of solid and cystic renal masses. J Urol 1998; 159: 1120-1133. 10. Kreft BP, Muller-Miny H, Sommer T, et al. Diagnostic value of MR imaging in comparison to CT in the detection and differential diagnosis of renal masses: ROC analysis. European Radiology 1997; 7(4): 542-554. (Level III evidence) 11. Semelka RC, Shoenut JP, Kroeker MA, MacMahon RG, Greenberg HM. Renal lesions: controlled comparison between CT and 1.5-T MR imaging with nonenhanced and gadolinium-enhanced fat suppressed spin-echo and breath-hold FLASH techniques. Radiology 1992; 182: 425- 430. (Prospective study 38 patients – Level II/III evidence) 12. Richter F, Kasabian NG, Irwin RJ Jr, et al. accuracy of diagnosis of guided biopsy of renal mass lesions classified indeterminate by imaging studies. Urology 2000; 55: 348-352. (Retrospective study 583 patients with indeterminate renal mass lesions – Level II/III evidence) 13. Wood BJ, Khan MA, McGovern F, Harisinghani M, Hahn PF, Mueller PR. Imaging guided biopsy of renal masses: indications, accuracy and impact on clin- ical management. J Urol 1999; 161: 1470-1474. (Retrospective study cohort of 73 patients – Level III evidence) 14. Niceforo J, Coughlin BE. Diagnosis of renal cell carcinoma: value of fine-needle aspiration cytology in patients with metastases or contraindications to nephrectomy. AJR 1993; 161: 1303-1305. (Retrospective study cohort of 55 consecutive patients – Level III evidence).

192 Further Reading 1. Fowler C, Reznek RH. The indeterminate renal mass. Imaging 2001; 13: 27-43. 2. Zagoria RJ, Dyer RB. The small renal mass: detection, characterization, and management. Abdom Imaging 1998; 23: 256-265

193 SCROTAL MASS

COLOUR DOPPLER ULTRASOUND • Indications: 1 • To confirm a clinical diagnosis of tumour and to assess contralateral testis. • To assess clinically solid scrotal masses. • To assess an impalpable testis within a hydrocoele. • To confirm a boderline clinical diagnosis of varicocoele in appropriate patients. • Used to differentiate between intra- and extra-testicular masses and can differentiate fluid filled lesions (eg hydrocoele, spermatocoele, haematocoele etc.) from solid intra-testicular tumours when clinical evaluation is in doubt. 2 • 98% sensitivity and specificity for diagnosis of intra-scrotal neoplasia. 3 • Limitations: hypervascularity of large tumours can be difficult to distinguish from that of inflammatory lesions. 4, 5

COMPUTED TOMOGRAPHY • Abdominal CT is the imaging modality of choice for staging of patients with testicular cancer. 6 • Allows assessment of the retroperitoneum for the presence of metastatic disease. 6

194 • Accuracy ranges between 73-97% with false-negative rates of 23-44%. 7-9 • Chest CT is indicated when: 6, 8, 10, 11 1. Abdominal CT is positive. 2. Tumour markers are persistently elevated. 3. CXR findings are suspicious of pulmonary metastases. • Limitations: inability to detect metastatic disease in normal sized lymph nodes, and difficult interpretation in young men with paucity of retroperitoneal fat. 6

CHEST RADIOGRAPH • Initial screening study of choice for detecting pulmonary metastases in all patients with seminoma, and in negative abdominal CT patients with non-seminoma. 9-11

195 REFERENCES 1. Adeyoju AB, Collins GN, Pollard AJ, et al. A prospective evaluation of scrotal ultrasonography in clinical practice. BJU International 2000; 86: 87-88. (Prospective study 48 consecutive patients – Level II evidence) 2. Lau MWM, Taylor PM, Payne SR. The indications for . British Journal of Radiology 1999; 72: 833-837. (Retrospective study 160 patients – Level III evidence) 3. Guthrie JA, Fowler RC. Ultrasound diagnosis of testicular tumours presenting as epididymal disease. Clin Radiology 1992; 46: 397-400. (Prospective study 610 patients – Level II evidence) 4. Horstman WG, Melson GL, Middleton WD, et al. Testicular tumours: findings with colour doppler US. Radiology 1992; 185(3): 733-737. (Cohort of 28 patients – Level IV evidence) 5. Mazzu D, Jeffery Jr RB, Ralls PW. Lymphoma and leukemia involving the testicles: findings on gray-scale and colour doppler sonography. AJR 1994; 164: 645-647. ( Retrospective study 8 case controls – Level IV evidence) 6. Gatti JM, Stephenson RA. Staging of testis cancer: combining serum markers, histologic parameters, and radiographic imaging. Urologic Clinics of North America 1998; 25 (3): 397-403. 7. Richie JP, Garnick MB, Finberg H. Computerised tomography: how accurate for abdominal staging of testis tumours? J Urol 1982; 127: 715-717. (Prospective study 30 patients – Level II/III evidence) 8. Moul JW. Proper staging techniques in testicular cancer. Techniques in Urology 1995; 1: 126-132. 9. Samuelson L, Frostberg L, Olson A. Accuracy of radiological staging procedures in nonseminomatous testis cancer compared with findings from surgical exploration and histopathological studies of extirpated tissue. Br J Radiology 1986; 59: 131-134. (Retrospective study 48 patients – Level III evidence) 10. See WA, Hoxie L. Chest staging in testis cancer patients: imaging modality selection based upon risk assessment as determined by abdominal CT scan results. J Urol 1993; 150: 874-878. (Retrospective study 155 patients no controls – Level III evidence) 11. Fernandez EB, Colon E, McLeod DG, et al. Efficacy of radiographic chest imaging in patients with testicular cancer. Urology 1994; 44: 243-249. (Retrospective study 210 patients – Level III evidence)

196 ACUTE SCROTAL PAIN

ACUTE SCROTAL PAIN • Differential diagnoses include: 1 1. Torsion of the testis 2. Torsion of the testicular appendages 3. Acute epididymitis 4. Mumps orchitis 5. Strangulated hernia 6. Inflammatory type of testicular tumour 7. Acute hydrocele 8. Traumatic haemorrhage • Imaging is useful in the investigation of acute scrotal pain: 2 1. If there is a clinical doubt as to the cause of the acute scrotal pain or 2. If there is failure to respond to treatment. • Acute testicular torsion is a clinical diagnosis and prompt diagnosis is critical, as it requires urgent surgical intervention. Radiological investigations should not delay surgery. 3 • If imaging does not provide a clear diagnosis, patient should be surgically explored. 3

COLOUR DOPPLER ULTRASOUND • “Gold” standard in the diagnostic imaging of testicular torsion (sensitivity 82-90% and specificity approaching 100%). 4-6 • Reliably assesses blood flow within the testis. In testicular torsion, blood flow is markedly reduced or absent. 4 • In suspected epididymo-orchitis, US allows: 2 1. Confirmation of the diagnosis. 2. Excludes testicular torsion.

197 3. Scrotal assessment if there is difficulty in palpating the epididymis separately from the other intrascrotal structures. 4. Monitor complications such as infarction or abscess, which may require surgical intervention. • US features of epididymitis include: 7 1. Epididymal enlargement. 2. Hypoechogenicity. 3. Skin thickening. 4. Increased blood flow (hypervascularity of epididymis and/or testicle has a sensitivity of 91-100% for epididymitis +/- orchitis). 8 • Helps localise a scrotal swelling (testicular or extra-testicular). 1, 9 • >98% sensitivity for testicular neoplasms (which may present with pain). 9 • Limitations: 4, 6, 10 • False negatives in incomplete torsion and in spontaneous de-torsion. • Occasional inability to demonstrate flow in a normal testis. • Discordant epididymal and scrotal flow in spermatic cord torsion. • Flow in patients with testicular necrosis.

NUCLEAR MEDICINE SCAN • Used to clarify the perfusion if there is uncertainty on the colour Doppler ultrasound. 1 • 90-100% sensitivity and specificity for distinguishing ischaemia from infection. 11 • Uncommonly requested nowadays given the high accuracy of colour Doppler ultrasound. • Limitations: slightly lower specificity in the diagnosis of ischaemia versus other photon deficient lesions, such as hydrocele, spermatocele, oedematous appendix testis and inguinal hernia that can be mistaken for an avascular testis. 12 • Disadvantages: requires interpretative experience and careful technique and must be performed in a timely manner.

198 REFERENCES 1. Burgher LCDR SW. Acute scrotal pain. Emerg Med Clinics of North America 1998; 16(4): 781-809. 2. Lau MWM, Taylor PM, Payne SR. The indications for scrotal ultrasound. Br J Radiology 1999; 72: 833-837. (Retrospective study cohort of 160 patients referred for scrotal US – Level II/III evidence) 3. Hendrikx AJM, Dang L, Vroegindeweij D, et al. B-mode and colour-flow duplex ultrasonography: a useful adjunct in diagnosing scrotal disease? Br J Urol 1997; 79: 58-65. (Prospective study 215 consecutive patients – Level II/III evidence) 4. Wilbert DM, Schaerfe CW, Stern WD, et al. Evaluation of the acute scrotum by color-coded doppler ultrasonography. J Urol 1993; 149(6): 1475-1477. (Prospective study 40 patients – Level II evidence) 5. Suzer O, Ozcan H, Kupeli S, et al. Colour Doppler imaging in the diagnosis of the acute scrotum. Eur Urol 1997; 32(4): 457-461. (Retrospective study 102 consecutive patients – Level II evidence) 6. Burks DD, Markey BJ, Burkhard TK, et al. Suspected testicular torsion and ischaemia: evaluation with color Doppler sonography. Radiology 1990; 175(3): 815- 821. (Cohort of 32 patients – Level III evidence) 7. Oyen RH. Scrotal ultrasound. Eur Radiology 2002; 12: 19-34. 8. Horstman WG, Middleton WD, Melson GL. Scrotal inflammatory disease: color doppler US findings. Radiology 1991; 179: 55-59. (Cohort of 45 patients – Level II/III evidence) 9. Guthrie JA, Fowler RC. Ultrasound diagnosis of testicular tumors presenting as epididymal disease. Clin Radiology 1992; 46: 397-400. (Prospective study 610 patients - Level II evidence) 10. Allen TD, Elder JS. Shortcomings of color Doppler sonography in the diagnosis of testicular torsion. J Urol 1995; 154(4): 1508-1510. (Case series of 5 patients – Level IV evidence) 11. Melloul M, Paz A, Lask D, et al. The value of radionuclide scrotal imaging in the diagnosis of the acute testicular torsion. Br J Urol 1995:76(5): 628-631. (Prospective study 87 patients – Level II evidence) 12. Lutzker LG, Zuckier LS. Testicular scanning and other applications of radionuclide imaging of the genital tract. Semin Nucl Med 1990; 20(2): 159-188.

Further Reading 1. Pavlica P, Barazzi L. Imaging of the acute scrotum. Eur Radiol 2001; 11:220-228.

199 STAGING OF PROSTATE CARCINOMA

STAGING OF PROSTATE CANCER • Prostate cancers are located in the peripheral zone of the gland in 85%, in the transitional zone in 10%; 40-50% are multifocal. • Staging of prostate cancer is controversial. 1 • Digital rectal exam, tumour grade (biopsy Gleason score) and PSA levels are more important predictors than imaging in deciding the treatment of prostate cancer. 1-4 • Accurate staging is critical to the management of patients with prostate cancer. 5, 6 • In patients treated by radical prostatectomy, seminal vesicle involvement or extracapsular extension are often associated with recurrent disease. 5 • The surgical margin status and extent of extracapsular disease may influence the disease-free survival of patients treated with radical prostatectomy or may alter surgical approaches with respect to neurovascular bundle preservation. 6

PROSTATE SPECIFIC ANTIGEN LEVEL (PSA) • Correlates with the risk of extra-capsular extension, seminal vesicle invasion, and both regional and distant disease and predicts response to local therapy. 4 • Levels of 10ng/ml or less are strong predictors of negative bone scans. 7, 8 • Limitations: urinary tract infections, instrumentation, catherisation and benign prostatic hyperplasia may also cause PSA levels to rise.

TRANSRECTAL ULTRASOUND (TRUS) • TRUS alone is of limited value in staging of prostate cancer (46-66% accuracy). 9-12

200 • Most useful in performing systematic prostatic biopsies and biopsies of identifiable prostatic lesions and suspicious appearing periprostatic soft tissues, including the seminal vesicles. 3

COMPUTED TOMOGRAPHY (CT) • Routine CT is generally not indicated for the vast majority of patients with newly diagnosed prostate cancer for whom the incidence of positive lymph nodes is very low. 13, 14 • Useful in guiding the needle biopsy of pelvic lymph nodes. • Limitations: CT identification of pelvic adenopathy depends upon lymph node enlargement, and the correlation between nodal size and metastatic involvement is poor (30-35% sensitivity for detecting positive nodes). 15, 16

BONE SCAN • Routine use of a bone scan is not indicated for staging clinically localised prostate cancer when associated with low PSA levels as low PSA levels correlate well with absence of bony metastases. 7, 8 • Indicated in patients who have the history or clinical examination suggestive of bony involvement or high PSA levels (> 10ng/ml) or in advanced local disease or high grade disease as metastatic disease is significantly more common in this group and they may have low levels of PSA. 4, 17

ENDORECTAL MRI • Potential role as a staging modality for the identification of patients with extracapsular extension. 18 • Multicoil MRI is useful for defining patients that may benefit from the surgery and may also help in evaluating the risk of positive margin, especially in apical resection. 11 • High accuracy (89%) for detection of seminal vesical invasion. 11,19 • Low sensitivity for detection of minor capsular penetration of the tumour. 19 • More sensitive but less specific than TRUS for detection of extracapsular extension and seminal vesicle invasion of prostate carcinoma. 10, 12, 18, 20 • Addition of 3D proton MR spectroscopic imaging improves accuracy and reduces interobserver variability. 21 • Recent decision analysis found MR staging to be cost-effective for men with moderate or high probability of extracapsular disease. 22

201 REFERENCES 1. O’Dowd GJ, Veltri R, Orozco R, et al. Update on the appropriate staging evaluation for newly diagnosed prostate cancer. J Urol 1997; 158: 687-698. (Literature review 142 studies – Level II/III evidence) 2. Partin AW, Kattan MW, Subong EN, et al. Combination of prostate specific antigen, clinical stage, and Gleason score to predict pathological stage of localized prostate cancer: A multi-institutional update. JAMA 1997; 277: 1445-1451. (Prospective study 4133 consecutive patients - Level II evidence) 3. Narayan P, Gajendra V, Taylor SP, et al. The role of transrectal ultrasound-guided biopsy-based staging, preoperative serum prostate-specific antigen and biopsy Gleason score in prediction of final pathologic diagnosis in prostate cancer. Urology 1995; 46: 305-212. (Retrospective study cohort of 813 patients – Level II/III evidence) 4. American Urological Association (AUA). Prostate-specific antigen (PSA) best practice policy. Oncology 2000; 14(2): 267-286. 5. Epstein JI, Carmichael MJ, Walsh PC. Adenocarcinoma of the prostate invading the seminal vesicles: definition and relation to tumor volume, grade and margin of resection to prognosis. J Urol 1993; 149: 1040-1045. 6. Epstein JI, Carmichael MJ, Pizov G, et al. Influence of capsular penetration on progression following radical prostatectomy: a study of 196 cases with long term follow-up. J Urol 1993; 150: 135-141. 7. Oesterling JE, Martin SK, Bergstralh EJ, et al. The use of prostate-specific antigen in staging patients with newly diagnosed prostate cancer. JAMA 1993; 269: 57-60. (Retrospective study cohort of 2064 consecutive patients – Level II/III evidence) 8. Gleave ME, Coupland D, Drachenberg D, et al. Ability of serum prostate-specific antigen levels to predict normal bone scans in patients with newly diagnosed prostate cancer. Urology 1996; 47: 708-712. (Retrospective study cohort 490 patients – Level III evidence) 9. Rifkin MD, Zerhouni EA, Gatsonis CA, et al. Comparison of magnetic resonance imaging and ultrasonography in staging early prostate cancer. Results of a Multi- institutional Cooperative Trial. NEJM 1990; 323: 621-626. (Prospective study 230 consecutive patients – Level II evidence) 10. May F, Treumann TM, Dettmar P, et al. Limited value of endorectal magnetic resonance imaging and transrectal ultrasonography in the staging of clinically localized prostate cancer. BJU International 2001; 87: 66-69. (Prospective study 54 patients- Level III evidence) 11. Sanchez-Chapado M, Angulo J, Ibarburen C, et al. Comparison of digital , transrectal ultrasonography, and multicoil magnetic resonance imaging for preoperative evaluation of prostate cancer. Eur Urol 1997; 32: 140-149. (Prospective study 20 consecutive patients – Level II/III evidence) 12. Presti JC Jr, Hricak H, Narayan PA, et al. Local staging of prostatic carcinoma: comparison of transrectal sonography and endorectal MR imaging. AJR 1996; 166: 103-108. (Prospective study 56 patients – Level III evidence) 13. Levran Z, Gonzalez JA, Diokno AC, et al. Are pelvic computed tomography, bone scan, and pelvic lymphadenectomy necessary in the staging of prostatic cancer? Br J Urol 1995; 75: 778-781. (Retrospective study cohort of 861consecutive patients – Level II/III evidence) 14. Perrotti M, Pantuck A, Rabbani F, et al. Review of staging modalities in clinically localized prostate cancer. Urology 1999; 54: 208-214. 15. Wolf JS Jr, Cher M, Dall’era M, et al. The use and accuracy of cross-sectional imaging and fine needle aspiration cytology for detection of pelvic lymph node

202 metastasis before radical prostatectomy. J Urol 1995; 153: 993-999. (Retrospective study 174 patients – Level III evidence) 16. Flanigan RC, Mckay TC, Olson M, et al. Limited efficacy of preoperative computed tomographic scanning for the evaluation of lymph node metastasis in patients before radical prostatectomy. Urology 1996; 48: 428-432. (Retrospective study 173 consecutive patients – Level III evidence) 17. Bruwer G, Heyns CF, Allen FJ. Influence of local tumour stage and grade on reliability of serum prostate-specific antigen in predicting skeletal metastases in patients with adenocarcinoma of the prostate. Eur Urol 1999; 35: 223-227. (Retrospective study 450 consecutive patients – Level II evidence) 18. D’Amico AV, Schnall M, Whittington R, et al. Endorectal coil magnetic resonance imaging identifies advanced prostate cancer in select patients with clinically localized disease. Urology 1998; 51: 449-454. (Cohort of 49 patients – Level III evidence) 19. Ikonen S, Karkkainen P, Kivisaari L, et al. Magnetic resonance imaging of clinically localized prostatic cancer. J Urol 1998; 159: 915-919. (Retrospective study 51 consecutive patients – Level II/III evidence) 20. Tempany CM, Zhou X, Zerhouni EA, et al. Staging of prostate cancer: results of radiology diagnostic oncology group project comparison of three different MR imaging techniques. Radiology 1994; 92: 47-54. (Prospective study 213 patients with prostate cancer – Level II evidence) 21. Yu KK, Scheidler J, Hricak H, et al. Prostate cancer: prediction of extracapsular extension with endorectal MR imaging and three-dimensional proton MR spectroscopic imaging. Radiology 1999; 213: 481-488. (Retrospective study 53 patients – Level III evidence) 22. Jager GJ, Severens JL, Thornbury JR, et al. Prostate cancer staging: should MR imaging be used? – A decision analytic approach. Radiology 2000; 215: 445-451. (Decision analysis – Level II/III evidence)

203 STAGING OF RENAL CELL CARCINOMA

STAGING OF RENAL CELL CARCINOMA • The goal of imaging in patients with renal cell carcinoma is to separate candidates for surgical cure from those with advanced disease. 1 • For surgical candidates, imaging allows delineation of the extent of disease for treatment planning. 1 • Renal cell carcinoma staging system 1

Robson Disease extent TNM Stage Stage I Tumour confined to kidney (<2.5cm) T1 Tumour confined to kidney (>2.5cm) T2 II Tumour spread to perinephric fat or adrenal T3a IIIA Tumour spread to renal vein T3b Tumour spread to inferior vena cava T3c IIIB Tumour spread to local lymph nodes (LN) N1-3 M0 IIIC Tumour spread to local vessels and LNs T3b N1-3 IVA Tumour spread to adjacent organs T4a (Except ipsilateral adrenal) IVB Distant metastases M1 N4

COMPUTED TOMOGRAPHY (CT) • Initial investigation of choice for staging of renal cell carcinoma. 1-3 • 85-91% sensitivity for detecting caval thrombus. 3-5 • Limitations: poor differentiation between stage I disease and stage II disease (little significance in treatment planning). 4

PLAIN CHEST RADIOGRAPHS • Used as a screen for metastatic disease in renal cell carcinoma. 1 • A standard frontal and lateral chest radiograph excludes most pulmonary metastases. 1

204 DOPPLER ULTRASOUND • Useful adjunct to CT for delineating intrahepatic extension of inferior vena caval tumour or when tumour extends into the atrium of the heart (sensitivity approaching 100% for delineating tumour thrombus in the intrahepatic or suprahepatic inferior vena cava). 6-9 • Advantages: 1 • Non-invasive • No exposure to ionising radiation. • Does not require contrast material. • Relatively inexpensive and widely available. • Limitations: • Inferior to CT and MRI for overall staging of renal adenocarcinoma (low sensitivity for detection of tumour thrombus in the infrahepatic inferior vena cava or distal renal vein). 10, 11 • Image distortion secondary to bowel gas and fat.

MAGNETIC RESONANCE IMAGING • Most accurate method for assessing venous thrombus (83-100% sensitivity). 5,12-16 • Indicated when there is equivocal renal vein or inferior vena caval involvement on CT. 5, 12 • Advantages: 1 • Multiplanar imaging. • Superior soft tissue contrast. • Does not require intravascular contrast material. • No exposure to ionising radiation. • Disadvantages: limited availability and high expense.

CHEST COMPUTED TOMOGRAPHY (Chest CT) • Indications: 17 • When the chest radiograph is suspicious or positive or • In large and locally aggressive tumours to help confirm or exclude metastases and defining the extent of disease.

BONE SCAN • Routine bone scans are not warranted and should be reserved for patients with an elevated alkaline phosphatase, bone pain, or an extremely large and aggressive tumour. 2, 18

205 REFERENCES 1. Zagoria RJ, Bechtold RE. The role of imaging in staging renal adenocarcinoma. Seminars in US, CT, and MRI 1997; 18(2): 91-99. 2. Benson MA, Haaga JR, Resnick MI. Staging renal carcinoma. What is sufficient? Arch Surg 1989; 124(1): 71-73. (Retrospective study cohort of 64 patients – Level II/III evidence) 3. Dinney CPN, Lannon SG, Awad SA, et al. Analysis of imaging modalities, staging systems, and prognostic indicators for renal cell carcinoma. Urology 1992; 39(2): 122-129. (Retrospective study 314 patients – Level II evidence) 4. Johnson CD, Dunnick NR, Cohan RH, et al. Renal adenocarcinoma: CT staging of 100 tumours. AJR 1987; 148(1): 59-63. (Retrospective study cohort of 97 patients with renal cell carcinomas – Level III evidence) 5. Fein AB, Lee JKT, Balfe DM. Diagnosis and staging of renal carcinoma: a comparison of MR imaging and CT. AJR 1987; 148(4): 749-753. (Retrospective study 27 patients – Level II/III evidence) 6. Habboub HK, Abu-Yousef MM, Williams RD, et al. Accuracy of color Doppler sonography in assessing venous thrombus extension in renal cell carcinoma. AJR 1997; 168: 267-271. (Cohort of 44 patients – Level II/III evidence) 7. Kallman DA, King BF, Hattery RR, et al. Renal vein and inferior vena cava tumour thrombus in renal cell carcinoma: CT, US, MRI, and venacavography. J Comput Assist Tomogr 1992; 16:240-247. 8. Didier D, Racle A, Etievent JP, et al. Tumour thrombus of the inferior vena cava secondary to malignant abdominal neoplasms: US and CT evaluation. Radiology 1987; 162: 83-89. (Cohort of 19 patients – Level III evidence) 9. Schwerk WB, Schwerk WN, Rodeck G. Venous renal tumour extension: a prospective US evaluation. Radiology1985; 156:491-495. (Prospective study 120 consecutive patients – Level II evidence) 10. Fritzsche PJ, Millar C. Multimodality approach to staging renal cell carcinoma. Urol Radiol 1992; 14: 3-7. 11. Webb J, Murray A, Bary P, et al. The accuracy and limitations of ultrasound in the assessment of venous extension in renal carcinoma. Br J Urol 1987; 60: 14-17. 12. Hricak H, Thoeni RF, Carroll PR, et al. Detection and staging of renal neoplasms: a reassessment of MR imaging. Radiology 1988; 166; 643-649. 13. Goldfarb DA, Novick AC, Lorig R, et al. Magnetic resonance imaging for assessment of vena caval tumor thrombi: a comparative study with venacavography and computerized tomography scanning. J Urol 1990; 144: 1100 –1104. 14. Amendola MA, King CR, Pollack HM, Gefter W, et al. Staging of renal carcinoma using MRI at 1.5 Telsa. Cancer 1990; 66 (1): 40-44. 15. Semelka RC, Shoenut JP, Magro CM, et al. Renal cancer staging: comparison of contrast enhanced CT and gadolinium enhanced fat-suppressed spin-echo and gradient echo MR imaging. J Magn Reson Imaging 1993; 3(4) 597-602. 16. Horan JJ, Robertson VN, Choyke PL, et al. The detection of renal carcinoma extension into the renal vein and the inferior vena cava: a prospective comparison of venography and MRI. J Urol 1989; 142(4): 943-947. 17. Lim DJ, Carter MF. Computerized tomography in the preoperative staging of pulmonary metastases in patients with renal cell carcinoma. J Urol 1993; 150 (4): 1112-1114. 18. Campell RJ, Broaddus SB, Leadbetter GW Jr. Staging of renal carcinoma: cost effectiveness of routine pre-operative bone scans. Urology 1985; 25(3): 326-329. (Retrospective study cohort of 42 patients – Level III evidence)

206 ACUTE LOW BACK PAIN OR NECK PAIN

CLINICAL HISTORY AND EXAMINATION • In most cases of back pain of less than 4 weeks’ duration, history and physical examination are sufficient. 1-4 • If clinical evaluation indicates critical diagnoses such as cauda equina syndrome, progressive neurological deficit, fracture, neoplasm, infection, chronic pain syndrome, persistent pain resulting from previous spinal surgery and extra-spinal conditions, then early referral to a specialist and investigation with imaging is recommended. 1-3 • In the absence of red flags, diagnostic testing is of limited utility because 90% of these patients’ symptoms will resolve within 4 weeks. Delaying diagnostic imaging for 6 weeks avoids unnecessary cost and radiation exposure. 1

Selective indications/redflags for radiography in acute low back pain are: 5-7 1. Trauma 2. Steroid use 3. Osteoporosis 4. Age >50yrs 5. IV drug use 6. Unexplained weight loss 7. Unexplained fever 207 8. Immunosuppression 9. History of cancer 10. Failure to improve 11. Suspected ankylosing spondylitis 12. Compensation factors

PLAIN SPINAL RADIOGRAPHY • Not recommended for routine evaluation of acute low back pain within the first month unless a finding from the history and clinical examination raises concern. 1,8 • Indicated when redflags raise concern for tumour, infection, or fracture. 1 • Generally, anteroposterior (AP) and lateral views are sufficient. 9 • May show degenerative changes with disc space narrowing, facet joint arthropathy, pars interarticularis defect and spondylolisthesis. 10 • Plain film findings often correlate poorly with low back symptoms. 8,11 • Plain films have low sensitivity for early cancer or infection. Therefore, early diagnosis should be made with bone scan, CT or MRI, for suspected tumour/infection, even if the plain radiographs are negative. 1

COMPUTED TOMOGRAPHY • Similar accuracy to that of MRI in detecting herniated discs and spinal stenosis but less sensitive than MRI for detection of infections, metastatic cancer and rare neural tumours.12,13 • Advantages (as compared to MRI): • Provides superior bony detail of the spine, particularly the facet and the posterior elements. • Less sensitive to patient movement. • Less expensive. • More widely available.

BONE SCAN • Investigation of choice in patients with known malignancy and back pain without neurological symptoms or signs. 14,15 • Improved accuracy with the addition of SPECT. 14,16,17 • Advantages: • Useful in detection of clinically suspected occult infection, neoplasm or vertebral fracture. 16-18 • Useful in differentiation of malignant from benign lesions. 15 • Allows screening for multiple skeletal lesions. • Shows physiological activity of the osseous lesion. • Limitations: lacks specificity • If the bone scan show equivocal lesions and plain films are negative or show benign changes only, then MRI is the next investigation of choice. 19

MAGNETIC RESONANCE IMAGING • Imaging modality of choice in diagnosing disc herniation/lesions, degenerative myelopathy and spinal cord lesions. 12, 13, 20 • Urgent MRI is indicated in patients with backpain and acute neurological deterioration (eg. in epidural compression of the spinal cord or cauda equina from tumour, infection, or haematoma). 21 • Clinical correlation of detected morphologic abnormalities is important as significant percentage of asymptomatic population may have these abnormalities. 22

208 • Advantages: no ionising radiation, superior soft tissue resolution and multiplanar imaging. • Limitations: limited availability and expensive.

CT MYELOGRAM • Alternative if there is contraindication to MRI or when MRI is unavailable or technically inadequate. • Comparable accuracy to that of MRI in diagnosing disc herniation. 13,14,22 • Disadvantages: invasive and requires use of contrast agent.

IMAGE GUIDED BONE BIOPSY • Indications for biopsy include: 23 1. Focal vertebral column lesion in a symptomatic or asymptomatic patients. 2. New vertebral body compression fracture. 3. Malignant-appearing lesion in a patient with known primary tumour, to discern metastatic spread versus a new additional primary tumour. 4. Confirmation of clinically and radiographically suspected osteomyelitis/discitis 5. Isolation of an organism in a patient with a diagnosis of osteomyelitis-discitis based on the radiographic and clinical findings. • ~70-80% accuracy in the evaluation of suspected metastatic lesions and infections. 24 • Cost-effective for suspected metastatic deposits and infections. 25 • Disadvantages: invasive, risk of tumour tracking and potential complications.

209 REFERENCES 1. Bigos S, Bowyer O, Braen G, et al. Acute low back problems in adults. Clinical practice guideline no.14. Rockville, Md: department of Health and Human Services; 1994. AHCPR publication no.95-0642. (Level II/III evidence) 2. American Academy of orthopaedic surgeons. Clinical guideline on low back pain. American Academy of orthopaedic surgeons 1999 (online). 3. Della-Giustina DA. Emergency department evaluation and treatment of back pain. Emergency Med Clinics of North America 1999; 17(4): 877-893. 4. Kerry S, Hilton S, Patel S, et al. Routine referral for radiography of patients presenting with low back pain: is patients’ outcome influenced by GPs’ referral for plain radiography? Health Technol Assess 2000; 4: 20. (Randomised controlled Trial 153 patients + 506 patients on observational study – level II evidence) 5. Deyo RA, Diehl AK. Lumbar spine films in primary care: current use and effects of selective ordering criteria. J Gen Intern Med 1986; 1: 20-25. (Prospective study 621 patients – Level II/III evidence) 6. Gibson M, Zoltie N. Radiography for back pain presenting to accident and emergency departments. Arch Emerg Med 1992; 9: 28-31. (Prospective study 225 consecutive patients – Level II evidence) 7. Scavone JC, Latshaw RF, Rohrar GV. Use of lumbar spine films: statistical evaluation at a university teaching hospital. JAMA 1981; 1105-1108. (Retrospective study 871 patients – Level III evidence). 8. Reinus WR, Strome G, Zwemer FL Jr. Use of lumbosacral spine radiographs in a level II emergency department. AJR 1998; 170: 443-447. (Prospective study 482 patients – Level II/III evidence) 9. Scavone JG, Latshaw RF, Widener WA. Anteroposterior and lateral radiographs: an adequate lumbar spine examination. AJR 1991; 136: 715-717. (Retrospective study 782 patients – Level III evidence) 10. Inaoka M, Yamazaki Y, Hosono N, et al. Radiographic analysis of lumbar spine for low-back pain in the general population. Arch Orthop Trauma Surg 2000; 120: 380- 385. 11. Van Tulder MW, Assendelft WJ, Koes BW, et al. Spinal radiographic findings and nonspecific low back pain. A systematic review of observational studies. Spine 1997; 22: 427-434. (Level III evidence) 12. Thornbury JR, Fryback DG, Turski PA, et al. Disk-caused nerve compression in patients with acute low-back pain: diagnosis with MR, CT myelography, and plain CT. Radiology 1993; 186: 731-738. (Prospective study 95 patients – Level III evidence) 13. Albeck MJ, Hilden J, Kjaer L, et al. A controlled comparison of myelography, computed tomography, and magnetic resonance imaging in clinically suspected lumbar disc herniation. Spine 1995; 20: 443-448. (Prospective blinded study 80 patients – Level II evidence) 14. Delpassand ES, Garcia JR, Bhadkamkar V, et al. Value of SPECT imaging of the thoracolumbar spine in cancer patients. Clinical Nucl Med 1995; 20(12): 1047-1051. (Prospective study 50 patients- Level II/III evidence) 15. Even-Sapir E, Martin RH, Barnes DC, et al. Role of SPECT in differentiating malignant from benign lesions in the lower thoracic and lumbar vertebrae. (Retrospective study 233 patients – Level II/III evidence) 16. Ryan PJ, Evans PA, Gibson T, et al. Chronic low back pain: comparison of bone SPECT with radiography and CT. Radiology 1992; 182: 849-854. (Prospective study 34 patients – Level III evidence)

210 17. Gates GF. SPECT imaging of the lumbosacral spine and pelvis. Clin Nucl Med 1988; 13: 907-914. (Prospective study 100 consecutive patients – Level II/III evidence) 18. Valdez DC, Johnson RG. Role of technetium-99m planar bone scanning in the evaluation of low back pain. Skeletal Radiology 1994; 23: 91-97. (Retrospective study cohort of 139 patients – Level III evidence) 19. Aitchison FA, Poon FW, Hadley MD, et al. Vertebral metastases and an equivocal bone scan: value of magnetic resonance imaging. Nucl Med Commun 1992; 13: 429-431. 20. Hashimoto K, Akahori O, Kitano K, et al. Magnetic resonance imaging of lumbar disc herniation: comparison with myelography. Spine 1990; 15: 1166-1169. (Retrospective study 53 patients case controls – Level IV evidence) 21. Lis E, Krol G, O’Malley B. emergency magnetic resonance imaging of the spine. Topics in Magnetic resonance imaging 1998; 9(4): 228-237. 22. Borenstein DG, O’Mara JW Jr, Boden S et al. The value of magnetic resonance imaging of the lumbar spine to predict low-back pain in asymptomatic subjects: a seven-year follow-up study. J Bone & J Surg 2001; 83-A (9): 1306-1311. (Prospective study 67 patients – Level II evidence) 23. Geremia G, Joglekar S. Percutaneous needle biopsy of the spine. Neuroimaging clinics of North America 2000; 10(3): 503-533. 24. Fraser-Hill MA, Renfrew DL. Percutaneous needle biopsy of musculoskeletal lesion. I. Effective accuracy and diagnostic utility. AJR 1992; 158: 809-812. (Cohort of 102 needle biopsies – Level II/III evidence) 25. Fraser-Hill MA, Ranfrew DL, Hilsenrath PE, et al. Percutaneous needle biopsy of musculoskeletal lesion. II. Cost-effectiveness. AJR 1992; 158: 813-818. (Level III evidence)

Further Reading 1. Atlas SJ, Deyo RA. Evaluating and managing acute low back pain in the primary care setting. J Gen Intern Med 2001; 16: 120-131. 2. Deyo RA, Weinstein JN. Low back pain. NEJM 2001; 344(5): 363-370. 3. Patel AT, Ogle AA. Diagnosis and management of acute low back pain. American Family Physician 2000; 61: 1779-1786, 1789-1790. 4. Boden S. Current concepts review - The use of radiographic imaging studies in the evaluation of patients who have degenerative disorders of the lumbar spine. J Bone & J Surg 1996; 78-A (1): 114-124. 5. Chakera TMH, McCormick CC. Radiology and low back pain. Australian Family Physician 1995; 24: 576-582.

211 BONE METASTASES

ISOTOPE BONE SCAN • Imaging modality of choice for the detection of bone metastases. 1,2 • In a patient with foci of increased uptake and a known primary tumour, the scan strongly suggests metastases. 1 • Advantages: allows total body survey. 1,2 • Limitations: • Radiographic correlation may be required in some patients with positive bone scan because of non specificity of findings on radioisotope imaging. 1 • Some metastases may not show increased uptake on bone scan, particularly those that are lytic, for example kidney, thyroid and melanoma. 1

PLAIN RADIOGRAPHY • Certain radiographic features may help to distinguish metastases from other conditions and aid in identification of the primary tumour. 1 • Limitations: poor sensitivity for detection of bone metastases. 2

REFERENCES 1. Rybak LD, Rosenthal DI. Radiological imaging for the diagnosis of bone metastases. Q J Nucl Med 2001; 45: 53-64. 2. Schaffer DL, Pendergrass HP. Comparison of enzyme, clinical, radiographic, and radiographic methods of detecting bone metastases from carcinoma of the prostate. Radiology 1976; 121: 431-434. (Retrospective study 219 patients with prostate cancer who had bone scan – Level III evidence)

212 CELLULITIS WITH SUSPECTED BONE INFECTION

CELLULITIS WITH SUSPECTED BONE INFECTION • Clinical findings are still the mainstay for suspecting the diagnosis of musculoskeletal infections, especially osteomyelitis. 1 • No single test has 100% specificity and sensitivity for every case of musculoskeletal infection. Depending on the age of the patient, presence of orthopaedic hardware, location of infection, and systemic conditions, the choice of imaging modalities must be tailored to the patient’s condition. 1

PLAIN RADIOGRAPHY • Initial modality for investigation of suspected osteomyelitis. 1,2 • May be normal in early stages of osteomyelitis because 30-50% loss of bone density is required before a radiograph becomes abnormal. 1 • Earliest radiographic finding is deep soft tissue swelling that may cause obliteration of the tissue planes. 1

213 • Characteristic bone changes (periosteal new bone, bone erosion etc) may take 10-14 days to appear. 1 • When changes are present they are often non-specific. 3 • Normal plain radiographs do not exclude osteomyelitis. • Guides the selection of subsequent imaging by determining if the suspected osteomyelitis is superimposed on some other process that requires more complex evaluation.

BONE SCAN • Next imaging study of choice for investigation of suspected osteomyelitis. 4 • High (>90%) sensitivity and specificity for detection of osteomyelitis in patients with normal radiographs. 4, 6 • Highly sensitive in early diagnosis of osteomyelitis (usually abnormal within 24hrs of the onset of symptoms). 4 • Allows differentiation of cellulitis from osteomyelitis or septic arthritis. 5 • Cellulitis is characterised by initially high soft tissue uptake in the flow and blood pool phases, with mild and diffuse bone uptake in the third phase. 5 • Osteomyelitis causes increased uptake in the earlier phases and focal intense uptake on the delayed images. 5 • Limitations: • Reduced specificity in a bone with pre-existing conditions, such as fractures, orthopaedic hardware, or arthropathy. 4,7,8,9

LABELLED WHITE CELL SCAN • High (>95%) sensitivity and specificity for acute osteomyelitis. 4,7,10,11 • Particularly useful in excluding infection in a previously violated site of bone such as post-traumatic, diabetic and postsurgical conditions. 4,7,10,11 • Correlation with three-phase bone scan is recommended and usually required for accurate localisation. 10,12 • More specific than and three-phase bone scan. 4,12 • Highly accurate in detection of osteomyelitis of the foot in patients with diabetes. 13,14 • Limitations: • Less sensitivity for chronic osteomyelitis. 9,15 • Low sensitivity for vertebral osteomyelitis. 16 • Normal bone marrow activity can confound image interpretation. • Complex preparation. • Higher cost. • Relatively higher radiation dose to the spleen.

GALLIUM SCAN • Alternative if labelled white cell study or MRI is not available. • Used in combination with bone scan to diagnose osteomyelitis in specific situations of possible spinal osteomyelitis. 5 • Similar sensitivity but improved specificity compared to bone scan alone. 4 • Criteria for diagnosing osteomyelitis are: 5 1. Gallium activity greater than bone scan uptake. 2. Discordant uptake. • Limitations: • High radiation dose.

214 • Poor spatial resolution. • 48-hr delayed imaging necessary for optimal Ga-67 scintigraphy. • Lacks specificity in evaluation for suspected osteomyelitis that is superimposed upon other diseases causing increased bone turnover. 9,12

COMPUTED TOMOGRAPHY • Useful in detection and localisation of sequestra, cortical destruction, periosteal proliferation, and soft tissue extension. 1

MAGNETIC RESONANCE IMAGING • Alternative if labelled white cell study is not available. • Comparable accuracy to that of labelled white cell study. 17,18 • Aids surgery by delineating sinus tracts and soft tissue abscesses, by differentiating osteomyelitis from cellulitis, and by disclosing the extent of intramedullary involvement. 17,19,20 • Superior to CT for evaluating the extent of infection. 17 • Advantages: 1 • No ionising radiation • High sensitivity in early stages • Rapid examination • High contrast resolution • Direct multiplanar imaging • Direct demonstration of bone marrow involvement • Accurate assessment of spinal canal involvement and soft tissue abscesses • Immediate visualisation of neural structures • Limitations: limited availability and high expense.

215 REFERENCES 1. Tehranzadeh J, Wong E, Wang F, et al. Imaging of osteomyelitis in the mature skeleton. Radiologic Clinics of North America 2001; 39(2): 223-250. 2. Elgazzar AH, Abdel-Dayem HM, Clark JD, et al. Multimodality imaging of osteomyelitis. Eur J Nucl Med 1995; 22: 1043-1063. 3. Tumeh SS, Aliabadi P, Weissman BN, et al. Disease activity in osteomyelitis: role of radiography. Radiology 1987; 165: 781-784. (Retrospective study cohort of 104 patients – Level III evidence) 4. Schauwecker DS. The scintigraphic diagnosis of osteomyelitis. AJR 1992; 158: 9- 18. (Review) 5. Turpin S, Lambert R. Role of scintigraphy in musculoskeletal and spinal infections. Radiologic Clinics of North America 2001; 39(2): 169-189. 6. Tumeh SS, Aliabadi P, Seltzer SE, et al. Chronic osteomyelitis: the relative roles of scintigrams, plain radiographs, and transmission computed tomography. Clin Nucl Med 1988; 13: 710-715. (Retrospective study 27 patients – Level III evidence) 7. Magnuson JE, Brown ML, Hauser MF, et al. In-111 labeled leukocyte scintigraphy in suspected orthopaedic prosthesis infection: comparison with other imaging modalities. Radiology 1988; 168: 235-239. (Retrospective study cohort of 98 patients – Level III evidence) 8. Esterhai JL, Goll SR, McCarthy KE, et al. Indium-111 leukocyte scintigraphic detection of subclinical osteomyelitis complicating delayed and nonunion long bone fractures: a prospective study. J Orthop Res 1987; 5: 1-6. 9. Schauwecker DS, Park H-M, Mock BH et al. Evaluation of complicating osteomyelitis with Tc-99m MDP, In-111 granulocytes, and Ga-67 citrate. J Nucl Med 1984; 25: 849-853. (Prospective study 57 consecutive patients – Level II evidence) 10. Kolindou A, Liu Y, Ozker K, et al. In-111 WBC imaging of osteomyelitis in patients with underlying bone scan abnormalities. Clin Nucl Med 1996; 21(3): 183- 191. (Retrospective study cohort of 87 patients – Level II/III evidence) 11. McCarthy K, Velchik MG, Alavi A, et al. Indium-111-labeled white blood cells in the detection of osteomyelitis complicated by a pre-existing condition. J Nucl Med 1988; 29: 1015-1021. (Retrospective study cohort of 46 patients – Level II/III evidence) 12. Seabold JE, Nepola JV, Conrad GR, et al. Detection of osteomyelitis at fracture nonunion sites: comparison of two scintigraphic methods. AJR 1989; 152: 1021- 1027. (Prospective study 49 consecutive patients – Level II/III evidence) 13. Larcos G, Brown ML, Sutton RT. Diagnosis of osteomyelitis of the foot in diabetic patients: value of 111-In-leukocyte scintigraphy. AJR 1991; 157: 527-531. (Retrospective study cohort of 51 patients – Level III evidence) 14. Johnson JE, Kennedy EJ, Shereff MJ, et al. Prospective study of bone, indium-111- labeled white blood cell and gallium-67 scanning for the evaluation of osteomyelitis in the diabetic foot. Foot Ankle Int 1996; 17: 10-16. (Prospective study 22 patients - Level III evidence) 15. Schauwecker DS. Osteomyelitis: diagnosis with In-111-labeled leukocytes. Radiology 1989; 171: 141-146. (Retrospective study cohort of 485 patients – Level III evidence) 16. Whalen JL, Brown ML, McLeod R, et al. Limitations of indium leuckocyte imaging for the diagnosis of spine infections. Spine 1991; 16: 193-197. (Retrospective study 22 patients – Level II evidence) 17. Tang JSH, Gold RH, Bassett LW, et al. Musculoskeletal infection of the extremities: evaluation with MR imaging. Radiology 1988; 166: 205-209. (Retrospective study cohort of 17 patients – Level III evidence)

216 18. Morrison WB, Schweitzer ME, Bock GW, et al. Diagnosis of osteomyelitis: utility of fat-suppressed contrast-enhanced MR Imaging. Radiology 1993; 189: 251-257. (Prospective study 50 patients – Level III evidence) 19. Rahmouni A, Chosidow O, Mathieu D, et al. MR imaging in acute infectious cellulitis. Radiology 1994; 192: 493-496. (Prospective study 36 patients – Level III evidence) 20. Hopkins KL, Li KCP, Bergman G. Gadolinium-DTPA-enhanced magnetic resonance imaging of musculoskeletal infectious processes. Skeletal Radiology 1995; 24:325-330. (Retrospective study 33 patients – Level III evidence)

Further Reading 1. Sammak B, Bagi AE, Al Shahed M, et al. Osteomyelitis: a review of currently used imaging techniques. Eur Radiol 1999; 9: 894-900. (Pictorial Review)

217 POST-TRAUMATIC KNEE PAIN OR INSTABILITY

CLINICAL DECISION RULES FOR RADIOGRAPHY IN ACUTE KNEE INJURY Two main validated clinical decision rules defining the guidelines for the appropriate use of radiographs in acute knee injuries are:

Ottawa knee rules: 1-4 • Order radiography of the knee if any of the following factors are present: 1. Age 55 years or older 2. Tenderness at head of 3. Isolated tenderness of patella 4. Inability to flex knee to 90 degrees 5. Inability to walk four weight-bearing steps immediately after the injury and in emergency department. • 97-100% sensitive for identifying knee fractures. 4, 5

Pittsburgh decision rules: 6 • Characteristics of patients who should undergo radiography after knee trauma: Blunt trauma or a fall as mechanism of injury plus either of the following: 1. Age younger than 12 years old or older than 50 years 2. Inability to walk four weight-bearing steps in the emergency department. • 99% sensitive and 60-79% specific for the diagnosis of knee fractures. 5, 6

According to studies published by Bauer 7 and Weber 8: • Clinically significant fracture can be excluded in patients older than 18 years old who can walk without limping or if there was a twisting injury to the knee and no joint effusion.

218 PLAIN RADIOGRAPHS • Initial imaging modality of choice for the evaluation of post-traumatic knee pain or instability. 9 • Four views (antero-posterior, lateral and both obliques) may detect subtle fractures or bony avulsions caused by detachments of the cruciate or collateral ligaments and can confirm the direction of dislocation. 9-11

ARTHROGRAPHY • 50-75% overall accuracy in the diagnosis of ligament and meniscal injuries of the knee. 12-14 • Cheapest investigation to screen out normal menisci. • Has been largely replaced by MRI. • Limitations: examination is limited to the surface evaluation of the meniscus. • Disadvantages: invasive, intra-articular injection of contrast media, ionising radiation and potential complications.

MAGNETIC RESONANCE IMAGING • Investigation of choice for the evaluation of post-traumatic knee pain or instability, when it is available. 15 • High accuracy in detection of: 1. Meniscal tears 16, 17 2. Cruciate ligament tears 16-18 3. Collateral ligamentous injuries 19 4. Bone bruises 20, 22 5. Osteochondral defects 21, 22 6. Chondromalacia patellae as well as less common pathologies • Cost-effective in reducing the number of diagnostic . 23-25 • Advantages: non-invasive, no ionising radiation, superior soft tissue contrast, ability to demonstrate both intra-articular and extra-articular abnormalities, multiplanar imaging and no anatomical restrictions to access. • Limitations: • Decreased diagnostic accuracy in patients with multiple injuries of the knee. 19, 26 • Limited availability and high expense.

COMPUTED TOMOGRAPHY • Comparable accuracy to that of MRI for the assessment of tibial plateau fractures. 27 • Useful in looking for loose bodies and retropatellar problems. • Multi-slice CT arthrography has a high diagnostic accuracy in detection of anterior cruciate ligament tears and associated meniscal lesions and articular pathology. 28 • Some institutions are using multi-slice CT arthrography as an alternative because of limited availability of MRI. 28

BONE SCAN • Can be used to detect radiographically occult post-traumatic bone injuries. 29 • Used extensively to assess chronic knee pathology. 30 • Focal increased uptake is noted at sites of bone repair such as in fracture sites, torn menisci, bone infarctions and avulsions of ligamentous insertions. 29-32 • Limitations: non-specific, and inferior in defining anatomical extent of injury.

219 REFERENCES 1. Stiell IG, Greenberg GH, Wells GA, et al. Derivation of decision rule for the use of radiography in acute knee injuries. Ann Emerg 1995; 26: 405-413. (Prospective study 1047 patients with acute knee injuries – Level II evidence) 2. Stiell IG, Greenberg GH, Wells GA, et al. Prospective validation of a decision rule for the use of radiography in acute knee injuries. JAMA 1996; 275: 611-615. (Prospective study 1096 patients – Level I/II evidence) 3. Stiell IG, Wells GA, Hoag RH, et al. Implementation of the ottawa knee rule for the use of radiography in acute knee injuries. JAMA 1997; 278(23): 2075-2079. (Prospective controlled trial 3907 consecutive patients – Level I/II evidence) 4. Emparanza JI, Aginaga JR. Validation of the . Ann Emerg Med 2001; 38(4): 364-368. (Prospective study 1522 patients – Level II evidence) 5. Seaberg DC, Yealy DM, Lukens T, et al. Multicenter comparison of two clinical decision rules for the use of radiography in acute, high-risk knee injuries. Ann Emerg Med 1998; 32: 8-13. (Prospective multicenter study 934 patients – Level II evidence) 6. Seaberg DC, Jackson R. Clinical decision rule for knee radiographs. Am J Emerg Med 1994; 12: 541-543. (Level II evidence) 7. Bauer SJ, Hollander JE, Fuchs SH, et al. A clinical decision rule in the evaluation of acute knee injuries. J Emerg Med 1995; 13(5): 611-615. (Level II/III evidence) 8. Weber JE, Jackson Re, Peacock WF, et al. Clinical decision rules discriminate between fractures and nonfractures in acute isolated knee trauma. Ann Emerg Med 1995; 26:429-433. (Level II/III evidence) 9. Potter HG. Imaging of the multiple-ligament-injured knee. Clinics Sports Medicine 2000; 19(3): 425-441. 10. Gray SD, Kaplan PA, Dussault RG, et al. Acute knee trauma: how many plain film views are necessary for the initial examination? Skeletal Radiology 1997; 26: 298- 302. (Retrospective study 90 patients with acute knee trauma – Level II/III evidence) 11. Delzell PB, Schils JP, Recht MP. Subtle fractures about the knee: innocous- appearing yet indicative of internal derangement. AJR 1996; 167: 699-703. (Pictorial essay) 12. Kulthanan T, Noiklang P. Arthrography and of the knee in sports injuries. Br J Sp Med 1993; 27(2): 87-89. (Cohort of 53 patients – Level III evidence) 13. Bonamo JJ, Shulman G. Double contrast arthrography of the knee, a comparison to clinical diagnosis and arthroscopic findings. Orthopaedics (PCM) 1988; 11: 1041- 1046. 14. Selesnick FH, Noble HB, Bachman DC, et al. Internal derangement of the knee: diagnosis by arthrography, , and arthrotomy. Clin Orthop 1985; 198: 26- 30. (Retrospective study 384 patients – Level III/IV evidence) 15. Kaplan PA, Dussault RG. Magnetic resonance imaging of the knee: menisci, ligament, tendons. Top Magn Reson Imaging 1993; 5(4): 228-248. 16. Munk B, Madsen F, Lundorf E, et al. Clinical magnetic resonance imaging and arthroscopic findings in : a comparative prospective study of meniscus, anterior cruciate ligament and cartilage lesions. Arthroscopy 1998; 14(2): 171-175. (Prospective study 61 patients – Level II/III evidence) 17. Fischer SP, Fox JM, Del Pizzo W, et al. Accuracy of diagnoses from magnetic resonance imaging of the knee: a multicenter analysis of one thousand and fourteen patients. J Bone Joint Surg 1991; 73-A (1): 2-10. (Cohort of 1014 patients – Level II/III evidence)

220 18. Ha TPT, Li KCP, Beaulieu CF, et al. Anterior cruciate ligament injury: fast spin- echo MR imaging with arthroscopic correlation in 217 examinations. AJR 1998; 170: 1215-1219. (Retrospective study cohort of 217 knee examinations – Level III evidence) 19. Rubin DA, Kettering JM, Towers JD, et al. MR imaging of knees having isolated and combined ligament injuries. AJR 1998; 170: 1207-1213. (Cohort of 340 consecutive injured knees – Level II/III evidence) 20. Kapelov SR, Teresi LM, Bradley WG, et al. Bone contusions of the knee: increased lesion detection with fast spin-echo MR imaging with spectroscopic fat saturation. Radiology 1993; 189: 901-904. (Prospective study 76 consecutive patients – Level II/III evidence) 21. Potter HG, Linklater JM, Allen AA, et al. Magnetic resonance imaging of articular cartilage in the knee. J Bone Joint Surgery 1998; 80-A (9): 1276-1284. (Retrospective study 88 patients – Level III/IV evidence) 22. Mink JH, Deutsch AL. Occult cartilage and bone injuries of the knee: detection, classification and assessment with MR imaging. Radiology 1989; 170: 823-829. (Retrospective study 66 patients – Level IV evidence) 23. Ruwe PA, McCarthy SM. Cost-effectiveness of magnetic resonance imaging of the knee. MRI Clinics of North America 1994; 2(3): 475-479. (Cohort of 103 consecutive patients – Level II/III evidence) 24. Bui-Mansfield LT, Youngberg RA, Warme W, et al. Potential cost savings of MR imaging obtained before arthroscopy of the knee: evaluation of 50 consecutive patients. AJR 1997; 168: 913-918. (Prospective study 50 consecutive patients – Level II evidence) 25. Vincken PWJ, ter Baak BPM, van Erkell AR, et al. Effectiveness of MR imaging in selection of patients for arthroscopy of the knee. Radiology 2002; 223: 739-746. (Prospective multicenter study 430 consecutive patients – Level II evidence) 26. De Smet AA, Graf BK. Meniscal tears missed on MR imaging: relationship to meniscal tear patterns and anterior cruciate ligament tears. AJR 1994; 162; 905-911. (Retrospective study 400 patients – Level III evidence) 27. Kode L, Lieberman JM, Motta AO, et al. Evaluation of tibial plateau fractures: efficacy of MR imaging compared with CT. AJR 1994; 163: 141-147. (Retrospective study 22 case controls – Level IV evidence) 28. Van de Berg BC, Lecouvet FE, Polivache P, et al. Anterior cruciate ligament tears and associated meniscal lesions: assessment at dual-detector spiral CT arthrography. Radiology 2002; 223: 403-409. (Retrospective study 125 consecutive patients – Level II/III evidence) 29. Giammarile F, masciocchi C, Barile A, et al. Three-phase radionuclide bone imaging and magnetic resonance imaging detection of occult knee fractures in athletes. Eur J Nucl Med 1994; 21(6): 493-496. (Cohort of 12 patients – Level III evidence) 30. Mooar P, Gregg J, Jacobstein J. Radionuclide imaging in internal derangements of the knee. Am J Sports Med 1987; 15: 132-137. (Prospective study 104 consecutive patients – Level II/III evidence) 31. Ryan PJ, Reddy K, Fleetcroft J. A prospective comparison of clinical examination, MRI, bone SPECT, and arthroscopy to detect meniscal tears. Clin Nucl Med 1998; 23(12): 803-806. (Prospective study cohort of 100 consecutive patients – Level II evidence) 32. Marks P, Goldberg JA, Vezina EC, et al. Subchondral bone infarctions in acute ligamentous knee injuries demonstrated on bone and magnetic resonance imaging. J Nucl Med 1992; 33: 516-520. (Prospective blinded study 13 athletes with knee trauma – Level II/III evidence)

221 Further Reading 1. Kaufman D, Leung J. Evaluation of the patient with extremity trauma: an evidence based approach. Emerg Med Clinics North America 1999; 17(1): 77-95. 2. Boden BP, Pearsall AW, Garrett WE Jr, et al. Patellofemoral instability: evaluation and management. J Am Acad Orthop Surg 1997; 5: 47-57.

222 MULTIPLE MYELOMA

PLAIN RADIOGRAPHY / • Primary method for the evaluation of skeletal involvement by multiple myeloma. 1, 2 • >90% sensitivity for detection of myeloma-related bone lesions. 1 • Provides detailed information about the nature of bone abnormalities and reveals the concomitant existence of osteolytic lesions, fractures and osteoporosis. 1 • Limitations: less sensitive than bone scan in areas such as ribs. 1

BONE SCAN • Useful adjunct to radiographs in cases with continued bone pain, unexplained by standard radiographs. 1, 2 • Hot spots suggest more osteoblastic disease, pathological fracture or other pathology. • Useful in demonstrating pathological fractures, particularly in areas those are not seen well on standard radiographs, such as the ribs. 1, 2 • May detect areas of early myeloma involvement that are not yet evident on the radiographs. 1, 2 • Limitations: poor sensitivity for detection of myeloma-related bone lesions and evaluating the extent of the disease. 1, 2 • Some centres use whole body sestamibi scan or F-18 FDG PET scan to evaluate the extent of the disease and monitor response to therapy. 3-5

MAGNETIC RESONANCE IMAGING (MRI) • Imaging modality of choice for the diagnostic workup of myeloma patients with neurological symptoms. 6 • Useful in specific situations such as marrow based lesions. 6 • Superior to radiographs for lesion detection in the spine and pelvis. 7

223 REFERENCES 1. Ludwig H, Kumpan W, Sinzinger H. Radiography and in multiple myeloma: a comparative analysis. Br J Radiol 1982; 55(651): 173-181. (Cohort of 41 patients – Level II/III evidence) 2. Woolfenden JM, Pitt MJ, Durie BGM, et al. Comparison of bone scintigraphy and radiography in multiple myeloma. Radiology 1980; 134: 723-728. (Retrospective study cohort of 51 patients – Level III evidence) 3. Pace Leonardo, Catalano L, Del Vecchio S, et al. Predictive value of technetium- 99m sestamibi in patients with multiple myeloma and potential role in the follow- up. Eur J Nucl Med 2001; 28: 304-312. (Retrospective study cohort of 30 patients – Level III evidence) 4. Svaldi M, Tappa C, Gebert U, et al. Technetium-99m-sestamibi scintigraphy: an alternative approach for diagnosis and follow-up of active myeloma lesions after high-dose chemotherapy and autologous stem cell transplantation. Ann Hematol 2001; 80(7): 393-397. (Cohort of 20 patients with monoclonal gammopathy and 46 myeloma patients – Level II/III evidence) 5. Orchard K, Barrington S, Buscombe J, et al. Fluoro-deoxyglucose positron emission tomography imaging for the detection of occult disease in multiple myeloma. Br J Haematology 2002; 117: 133-135. (3 case studies – Level IV evidence) 6. Lecouvet FE, Vande Berg BC, Malghem J, et al. Magnetic resonance and computed tomography imaging in multiple myeloma. Seminars in Musculoskeletal Radiology 2001; 5(1): 43-55. 7. Leucouvet FE, Malghem J, Michaux L, et al. Skeletal survey in advanced multiple myeloma: radiographic versus MR imaging survey. Br J Haematology 1999; 106: 35-39. (Cohort of 80 consecutive patients – Level II evidence)

224 SHOULDER PAIN / INSTABILITY

PLAIN RADIOGRAPHY • Initial investigation of choice for all shoulder problems. 1 • Can detect most fractures, dislocations, calcific tendonitis and other skeletal causes of pain such as arthritis and bone tumour. 1 • Different situations require different types of plain films (AP/Lateral/Axillary views): • Impingement views in clinically suspected impingement syndrome and/or rotator cuff tears to detect subacromial spur. 2 • Axial or anterior oblique views in trauma. 3, 4 • Routine axillary views in non-traumatised shoulder. 5

COMPUTED TOMOGRAPHY (CT) • Superior to plain radiographs in the evaluation of complex fractures and fracture- dislocations involving the head of the humerus. 6-8 • Allows planning of treatment of complex proximal humeral fractures. 6-8

CT ARTHROGRAPHY • Alternative for assessment of gleno-humeral instability (usually following dislocation) when MRI is unavailable. 9

225 • Allows accurate evaluation of capsule/labral disorders. 10-12

ULTRASONOGRAPHY (US) • High sensitivity and specificity (>90%) for detection and staging of rotator cuff tears. 13-15 • Comparable to MRI in the evaluation of full thickness rotator cuff tears. 16 • In many institutions, US has replaced MR imaging in the initial evaluation of rotator cuff. • May be considered in the evaluation of patients ≥40 years of age with primary traumatic anterior shoulder dislocation as rotator cuff tear is more common in this age group. 17 • Useful in guiding aspiration of calcium deposits or bursal injections. • Can detect minimally displaced greater tuberosity fractures. • Advantages: no ionising radiation, non-invasive, no contrast agent, relatively inexpensive and readily available. • Limitations: • Less sensitive for detecting partial thickness rotator cuff tears. 13-15 • Cannot accurately evaluate the labral-ligamentous complex.

MAGNETIC RESONANCE IMAGING (MRI) • Highly accurate for the evaluation of rotator cuff pathology. 18-20 • Indicated when further investigation of rotator cuff pathology is needed. • May be used in the investigation of rotator cuff disease when US expertise is unavailable. • Comparable to arthrography in its diagnostic and therapeutic impact in the evaluation of shoulder problems. 21 • Advantages: • No ionising radiation • Non-invasive • Multi-planar imaging • Demonstrates other lesions such as ACJ osteoarthritis and avascular necrosis. • Comprehensive display of soft tissue anatomy • Demonstration of the causes for impingement • Useful in characterisation and staging of bone tumours • Limitations: • Less sensitive for detection of partial tears. • Limited availability.

MR ARTHROGRAPHY (MRI following intra-articular injection of a dilute contrast agent - gadolinium) • Most accurate imaging modality for defining: 1. Rotator cuff pathology. 22 2. Labral/capsule abnormalities in gleno-humeral instability. 10, 23, 24 • Superior depiction of partial-thickness tears compared to conventional MRI. 22 • Disadvantages: invasive, limited availability and high expense.

226 REFERENCES 1. Stiles RG, Otte MT. Imaging of the shoulder. Radiology 1993; 188: 603-613. 2. Jim YF, Chang CY, Wu JJ, et al. Shoulder impingement syndrome: impingement view and arthrography study based on 100 cases. Skeletal Radiology 1992; 21: 449- 451. (Prospective study 100 patients – Level III evidence) 3. De Smet AA. Anterior oblique projection in radiography of the traumatized shoulder. AJR 1980; 134(3): 515-518. (Prospective study 132 consecutive shoulder examinations – Level II/III evidence) 4. Silfverskiold JP, Straehley DJ, Jones WW. Roentgenographic evaluation of suspected shoulder dislocation: prospective study comparing the axillary view and the scapular “Y” view. Orthopaedics 1990; 13(1): 63-69. (Cohort of 75 consecutive patients – Level II/III evidence) 5. De Smet AA. Axillary projects in radiography of the non-traumatized shoulder. AJR 1980; 134(3): 511-514. (Prospective study 239 consecutive shoulder examinations - –Level II/III evidence) 6. Castagno AA, Shuman WP, Kilcoyne RF, et al. Complex fractures of the proximal humerus: role of CT in treatment. Radiology 1987; 165(3): 759-762. (Retrospective study 17 patients – Level IV evidence) 7. Jurik AG, Alberchtsen J. The use of computed tomography with two- and three- dimensional reconstructions in the diagnosis of three- and four-part fractures of the proximal humerus. Clinical Radiology 1994; 49: 800-804. (Retrospective study 10 patients – Level IV evidence) 8. Billet FP, Schmitt WG, Gay B. Computed tomography in with special regard to the advances of three-dimensional display. Archives of orthopaedic and Traumatic Surgery 1992; 111; 131-137. 9. Nelson MC, Leather GP, Nirschl RP, et al. Evaluation of the painful shoulder: a prospective comparison of magnetic resonance imaging, computerized tomographic arthrography, ultrasonography, and operative findings. J Bone & Joint Surgery 1991; 73-A: 707-716. (Prospective study 21 patients – Level III evidence) 10. Chandnani V, Yeager T, de Berardino T, et al. Glenoid labral tears: prospective evaluation with MRI imaging, MR arthrography, and CT arthrography. AJR 1993; 161: 1229-1235. (Prospective study 30 patients – Level II/III evidence) 11. Wilson AJ, Totty WG, Murphy WA, et al. Shoulder joint: arthrographic CT and long-term follow up, with surgical correlation. Radiology 1989; 173: 329-333. (Retrospective study 101 patients – Level III evidence) 12. Rafii M, Firooznia H, Golimbu C, et al. CT arthrography of capsular structures of the shoulder. AJR 1986; 146: 361-367. (Cohort of 45 patients – Level III evidence) 13. Teefey SA, Hasan SA, Middleton WD, et al. Ultrasonography of the rotator cuff: a comparison of ultrasonographic and arthroscopic findings in one hundred consecutive cases. J Bone & Joint Surgery 2000; 82-A (4): 498-504. (Retrospective study cohort of 100 consecutive patients – Level III evidence) 14. Wiener SN, Seitz WH Jr. Sonography of the shoulder in patients with tears of the rotator cuff: accuracy and value for selecting surgical options. AJR 1993; 160: 103- 107. (Prospective study 225 patients – Level II/III evidence) 15. Brenneke SI, Morgan CJ. Evaluation of ultrasonography as a diagnostic technique in the assessment of rotator cuff tendon tears. Am J Sports Med 1992; 20: 287-289. (Prospective study 120 patients – Level III evidence) 16. Swen WAA, Jacobs JWG, Algra PR, et al. Sonography and magnetic resonance imaging equivalent for the assessment of full-thickness rotator cuff tears. Arthritis & Rheumatism 1999; 42: 2231-2238. (Prospective study 21 consecutive patients – Level III evidence)

227 17. Pevny T, Hunter RE, Freeman JR. primary traumatic anterior shoulder dislocation in patients 40 years of age and older. Arthroscopy 1998; 14: 289-294. (Cohort of 125 patients – Level III evidence) 18. Balich SM, Sheley RC, Brown TR, et al. MR imaging of the rotator cuff tendon: interobserver agreement and analysis of interpretive errors. Radiology 1997; 204: 191-194. (Retrospective study cohort of 222 patients who underwent MRI and arthroscopy – Level III evidence) 19. Quinn S, Sheley R, Demlow T, et al. Rotator cuff tendon tears: evaluation with fat- suppressed MR imaging with arthroscopic correlation in 100 patients. Radiology 1995; 195: 497-501. (Prospective study 100 patients – Level III evidence) 20. Iannotti JP, Zlatkin MB, Esterhai JL, et al. Magnetic resonance imaging of the shoulder: sensitivity, specificity, and predictive value. J Bone & Joint Surgery 1991; 73-A (1): 17-29. (Prospective study 127 patients – Level II/III evidence) 21. Blanchard TK, Bearcroft PW, Constant CR, et al. Diagnostic and therapeutic impact of MRI and arthrography in the investigation of full thickness rotator cuff tears. European Radiology 1999; 9: 638-642. (Prospective study 104 consecutive patients – Level II/III evidence) 22. Holder J, Kurunoglu-Brahme S, Snyder S, et al. Rotator cuff disease: assessment with MR arthrography versus standard MR imaging in 36 patients with arthroscopic confirmation. Radiology 1992; 182: 431-436. (Retrospective study 36 patients – Level III evidence) 23. Palmer WE, Brown JH, Rosenthal DI. Labral-ligamentous complex of the shoulder: evaluation with MR arthrography. Radiology 1994; 190: 645-651. (Prospective study 48 shoulders – Level III evidence) 24. Jee W-H, McCauley TR, Katz LD, et al. Superior labral anterior posterior (SLAP) lesions of the glenoid labrum: reliability and accuracy of MR arthrography for diagnosis. Radiology 2001; 218: 127-132. (Retrospective study 80 patients – Level III evidence)

228 ACUTE LOW BACK / NECK PAIN – CLINICALLY SUSPECTED INFECTION

PLAIN RADIOGRAPHY • 82% sensitivity and 57% specificity for vertebral osteomyelitis. 1 • May not be positive for weeks, in vertebral osteomyelitis, but eventually demonstrates disc space narrowing and endplate erosions. 2 • Subchondral bone erosions, destructions, regional sclerosis, osteopaenia, and gibbus formation are clearly visualised on plain radiographs. 2 • Limitations: • Frequently negative in the early phase of infection. 2 • False positives due to severe degenerative disease or resolved osteomyelitis. 1

BONE SCAN • >90% sensitivity for the detection of osteomyelitis and discitis. 1, 3-5 • Improved sensitivity and localising properties with SPECT imaging. 5 • Limitations: 2 • Non-specific for infection, trauma, tumour or degenerative changes. 1, 5 • Do not have the spatial resolution to define cortical bone loss, disc space narrowing, and involvement of adjacent vertebral bodies. • Cannot define small areas of paraspinous or epidural disease. • Not useful in follow-up due to increased activity even after spondylitis has healed.

229 GALLIUM SCAN • Used as a complement to bone scan to enhance the specificity of the study and to detect extraosseous sites of infection. 1, 3, 5-7 • Ga-67 whole body survey can be performed early in patients with non-localising symptoms of infection. If focal abnormality is detected then selective MRI can be used to confirm the diagnosis and to delineate the extent of infection. 8 • SPECT Ga-67 can be used alone to diagnose spinal osteomyelitis and soft tissue infection. 5, 9 • May demonstrate spinal infection in patients with negative MRI and high suspicion of spinal infection. 10 • Advantages: • Ga-67 alone can be used for follow-up. 6 • Aids in differentiating mild infection from degenerative disease. • Limitations: 48-hr delayed imaging necessary for optimal Ga-67 scintigraphy.

LABELLED WHITE CELL SCAN • Rarely used in investigation of suspected spinal infection. 7 • High specificity but low sensitivity (17%) for infective spondylitis. 11 • 66% overall accuracy for vertebral osteomyelitis when either increased or decreased activity used as criteria for infection. 4 • Useful for diagnosis of vertebral infection in patients who have not been treated with antibiotics previously. 11 • Limitations: • High rate of false negative studies in the presence of infective spondylitis. 11 • Difficult to differentiate infection of bony elements from that of soft tissues.

MAGNETIC RESONANCE IMAGING • Gadolinium enhanced MRI is the imaging modality of choice for the diagnosis and staging of infectious diseases of spine (>90% accuracy). 1, 10, 12-14 • Used to assess full soft-tissue extent of the infection and potential neural compromise, plan treatment and to monitor treatment response. 2 • Discloses morphological abnormalities of vertebral osteomyelitis earlier than other modalities and shortens the lag between patient presentation and final diagnosis. 1 • Evidence of involvement of two consecutive vertebrae and intervening disc is virtually diagnostic of infective spondylitis. 15 • Rim enhancement around abscess loculations within the vertebral bodies and/or paraspinal soft tissues is strongly suggestive of tuberculous spondylitis. 15 • Advantages: 15 • No ionising radiation • High sensitivity in early stages • High contrast resolution • Direct multiplanar imaging • Direct demonstration of bone marrow involvement • Accurate assessment of spinal canal involvement and soft tissue abscesses • Immediate visualisation of neural structures • Limitations: 15 • Low diagnostic specificity for distinguishing granulomatous myelitis and intradural extramedullary infections from neoplasia. • Difficult to differentiate infective myelitis from lesions such as sarcoidosis, multiple sclerosis, and idiopathic transverse myelitis.

230 • Pseudosparing of the end plate in infectious spondylitis. 16

BIOPSY • CT- guided percutaneous biopsy is an accurate method for identifying active bacterial disc space infections but is less reliable for identifying fungal infections. 17, 18

231 REFERENCES 1. Modic MT, Feiglin DH, Piraino DW, et al. Vertebral osteomyelitis: assessment using MR. Radiology 1985; 157: 157-166. (Prospective study 37 patients – Level II/III evidence) 2. Stabler A, Reiser MF. Imaging of spinal infection. Radiologic Clinics of North America 2001; 39(1): 115-135. 3. Lisbona R, Derbekyan V, Novales-Diaz J, et al. Gallium-67 scintigraphy in tuberculous and non tuberculous infectious spondylitis. J Nucl Med 1993; 34: 853- 859. (Retrospective study 21 patients – Level IV evidence) 4. Palestro CJ, Kim CK, Swyer AJ, et al. Radionuclide diagnosis of vertebral osteomyelitis: indium-111-leukocyte and technetium 99m-methylene diphosphonate bone scintigraphy. J Nucl Med 1991; 32: 1861. (Retrospective study 71 patients – Level III evidence) 5. Love C, Patel M, Lonner BS, et al. Diagnosing spinal osteomyelitis: a comparison of bone and Ga-67 scintigraphy and magnetic resonance imaging. Clinical Nuclear Medicine 2000; 25 (12): 963-977. (Retrospective study 22 patients – Level III evidence) 6. Hadjipavlou AG, Cesani-Vazquez F, Villaneuva-Meyer J, et al. The effectiveness of gallium citrate Ga-67 radionuclide imaging in vertebral osteomyelitis revisited. Am J Orthopaedics 1998; 179-183. 7. Palestro CJ, Torres MA. Radionuclide imaging in orthopaedic infections. Semin Nucl Med 1997; 28: 334. 8. Tzen KY, Yen TC, Yang RS, et al. The role of Ga-67 in the early detection of spinal epidural abscesses. Nuclear Medicine Communications 2000; 21: 165-170. (Retrospective study 6 patients – Level IV evidence) 9. Gratz S, Dorner J, Oestmann JW, et al. Ga-67-citrate and Tc-99m-MDP for estimating the severity of vertebral osteomyelitis. Nuclear Medicine Communications 2000; 21: 111-120. (Prospective study 30 patients – Level III evidence) 10. Jayraman S, Al-Nahhas AM, Vivian G, et al. Demonstration of spinal osteomyelitis with Ga-67 citrate, Tc-99m MDP, and Tc-99m ciprofloxacin with provisionally negative results on MRI. Clinical Nuclear Medicine 2000; 25: 224-226. (Case Report – Level IV/V evidence) 11. Whalen JL, Brown ML, McLeod R, et al. Limitations of indium leuckocyte imaging for the diagnosis of spine infections. Spine 1991; 16: 193-197. (Retrospective study 22 patients – Level II evidence) 12. Post MJD, Sze G, Quencer Rm, et al. Gadolinium-enhanced MR in spinal infection. J Comput Assist Tomogr 1990; 4: 721. 13. Maiuri F, Iaconetta G, Gallicchiio B, et al. Spondylodiscitis: clinical and magnetic resonance diagnosis. Spine 1997; 22(15): 1741-1746. (Retrospective study 65 case controls – Level IV evidence) 14. Post MJD. Quencer RM, Montalvo BM, et al. Spinal infection: evaluation with MR imaging and intraoperative US. Radiology 1988; 169: 765-771. (Retrospective study 24 case controls – Level IV evidence) 15. Sharif HS. Role of MR imaging in the management of spinal infections. AJR 1992; 158: 1333-1345. 16. Wolansky LJ, Heary RF, Patterson T, et al. Pseudosparing of the endplate: a potential pitfall in using MR imaging to diagnose infectious spondylitis. AJR 1999; 172: 777-780. (Retrospective study 19 patients – Level IV evidence) 17. Chew FS, Kline MJ. Diagnostic yield of CT-guided percutaneous aspiration procedures in suspected spontaneous infectious diskitis. Radiology 2001; 218: 211- 214. (Retrospective study cohort of 92 consecutive patients – Level II/III evidence)

232 18. Fouquet B, Goupille P, Gobert F, et al. Infectious discitis diagnostic contribution of laboratory tests and percutaneous discovertebral biopsy. Rev Rhum Engl Ed 1996; 63: 24-29.

Further Reading 1. Turpin S, Lambert R. Role of scintigraphy in musculoskeletal and spinal infections. Radiologic Clinics of North America 2001; 39(1): 169-190. 2. Varma R, Lander P, Assaf A. Imaging of Pyogenic infectious spondylodiskitis. Radiologic Clinics of North America 2001; 39(1): 203- 214.

233 SPINAL TRAUMA – CERVICAL

CLINICAL ASSESSMENT • Clinical factors such as mechanism of injury, associated injuries, and age, help define the risk of cervical spine fracture. 1 • Imaging is usually not indicated in patients, who meet the following low-risk clinical criteria for cervical spine fractures (NEXUS Criteria): 2 1. No midline cervical tenderness 2. No focal neurological deficit 3. Normal alertness 4. No intoxication 5. No painful distracting injury • Imaging is used in spinal trauma to detect and assess the extent of osseous, ligamentous, neural, and other soft-tissue injuries and to help evaluate instability. 3

PLAIN RADIOGRAPHY • Initial screening test of choice in the imaging evaluation of cervical spine trauma. 3-5 • ~80% accuracy for detection of cervical spine fractures. 6 • Generally, anteroposterior (AP), true lateral (including all seven cervical vertebrae and C7-T1 junction), and open-mouth odontoid views are adequate. 3-5 In some centres, oblique views are performed in addition to the above views.

234 • In patients with persistent cervical pain and suspected ligamentous injury and with normal radiographic examination should have functional views (flexion and extension views), to determine the stability of spine. 7 • Limitations: • High rate of diagnostic error (poor quality images and misinterpretation of the findings). 8, 9 • Difficulty obtaining technically adequate films in severely injured multiple trauma patients. 10 • Misses significant percentage of fractures, especially upper cervical spine fractures. 8, 11, 12

COMPUTED TOMOGRAPHY • Procedure of choice for the evaluation of possible fractures (98% sensitivity and 95% specificity for detection of cervical spine fractures). 4, 11, 13 • Most valuable for the assessment of bony injuries near the cervicothoracic junction and the base of skull, an area in which overlap interferes with the detection of fractures and misalignment, such as fractures of the occipital condyles, jefferson fracture and C1-2 rotatory dislocation. 12 • Useful in the following situations: 3, 9 1. To facilitate complete cervical spine evaluation in the face of inadequate plain films. 2. To clarify uncertain radiological findings on plain radiography. 3. To detect occult spinal fractures. 4. To determine the presence and degree of displacement of bony fragments into the neural canal. 5. To assess the spinal stability and to assist in operative planning • Recent studies have shown the superiority of helical CT over plain radiography when screening for cervical spine fractures in high risk patients (ie patients with neurological deficit or head injury or high-energy mechanism). 11, 13-15 • Advantages: 11 • Improved accuracy • Faster diagnosis. • Limitations: 16 • May miss fractures in the axial plane including base of odontoid and some subluxations. • Limited ability to show ligamentous injuries. • Increased radiation exposure.

MAGNETIC RESONANCE IMAGING • Procedure of choice for evaluating soft tissue, ligamentous and . 17- 19 • Indications: 3 1. Clinical evidence of spinal cord injury, especially incomplete injury 2. Neurological deficits not explained by plain film or CT findings 3. Patients with injuries requiring posterior stabilisation to exclude concomitant disc herniations that might alter the surgical approach. • MRI imaging factors such as haemorrhage, long segments of oedema and high cervical lesions correlate with poor functional recovery in patients with cervical spinal cord injury. 20 • Limitations: • Expensive

235 • Long imaging time • Inability to fully characterise vertebral fractures. 18 • Technical difficulties in clinically unstable patients. • Limited availability. • CT MYELOGRAPHY is an alternative if MRI is unavailable but carries a risk of complications because of invasive nature of the procedure.

236 REFERENCES 1. Hanson JA, Blackmore CC, Mann FA, et al. Cervical spine injury: A clinical decision rule to identify high-risk patients for helical CT screening. AJR 2000; 174: 713-717. (Clinical decision rule – Level II/III evidence) 2. Hoffman JR, Mower WR, Wolfson AB, et al. Validity of a set of clinical criteria to rule out injury to the cervical spine in patients with blunt trauma. NEJM 2000; 343: 94-99. (Large multicenter prospective study – Level II evidence) 3. Cornelius RS. Imaging of acute cervical spine trauma. Seminars Ultrasound, CT, and MRI 2001; 22(2): 108-124. 4. El-Khoury GY, Kathol MH, Daniel WW. Imaging of acute injuries of the cervical spine: value of plain radiography, CT, and MR imaging. AJR 1995; 164(1): 43-50. (Review) 5. Pasquale M, Fabian TC. Practice management guidelines for trauma from the Eastern Association for the surgery of trauma. J Trauma 1998; 44: 941-957. 6. Streitwieser DR, Knopp R, Wales LR, et al. Accuracy of standard radiographic views in detecting cervical spine fractures. Ann Emerg Med 1983; 12: 538-542. (Cohort of 71 patients – Level II/III evidence) 7. Lewis LM, Docherty M, Ruoff BE, et al. Flexion-extension views in the evaluation of cervical-spine injuries. Ann Emerg Med 1991; 20: 117-121. (Retrospective study 141 consecutive patients- Level II/III evidence) 8. Woodring JH, Lee C. Limitations of cervical radiography in the evaluation of acute cervical trauma. J Trauma 1993; 34: 32-39. (Retrospective study 216 case controls – Level IV evidence) 9. Borock EC, Gabram SGA, Jacobs LM, et al. A prospective analysis of a two-year experience using computed tomography as an adjunct for cervical spine clearance. J Trauma 1991; 31:1001-1006. (Prospective study 179 patients – Level II/III evidence) 10. Davis JW, Phreaner DL, Hoyt DB, et al. The eitiology of missed cervical spine injuries. J Trauma 1993; 34: 342-346. (Retrospective study cohort of 34 patients – Level IV evidence) 11. Nunez DB Jr, Ahmad AA, Coin CG, et al. Clearing the cervical spine in multiple trauma victims: a time-effective protocol using helical computed tomography. Emerg Radiol 1994; 1: 273-278. (Prospective study 800 patients – Level II evidence) 12. Schenarts PJ, Diaz J, Kaiser C, et al. Prospective comparison of admission computed tomographic scan and plain films of the upper cervical spine in trauma patients with altered mental status. J Trauma 2001; 51: 663-669. (Prospective unblinded study 1356 patients – Level III evidence) 13. Hanson JA, Blackmore CC, Mann FA, et al. Cervical spine injury: accuracy of helical CT used as a screening technique. Emergency Radiology 2000; 7: 31-35. (Retrospective study cohort of 601consecutive high-risk patients – Level II/III evidence) 14. Blackmore CC, Ramsey SD, Mann FA, et al. Cervical spine screening with computed tomography in trauma patients: a cost-effective analysis. Radiology 1999; 212: 117-125. (Retrospective study- decision analysis – Level III evidence) 15. Berne JD, Velmahos GC, El-tawil Q, et al. Value of complete cervical helical computed tomographic scanning in identifying cervical spine injury in the unevaluable blunt trauma patient with multiple injuries: a prospective study. J Trauma 1999; 47: 896-903. (Prospective study 48 patients – Level II evidence) 16. Woodring JH, Lee C. The role and limitations of CT scanning in the evaluation of the cervical trauma. J Trauma 1992; 33: 698-708. (Retrospective study 216 case controls – Level IV evidence)

237 17. Orrison WW Jr, Stimac GK, Stevens EA, et al. Magnetic resonance imaging evaluation of acute spine trauma. Emerg Radiol 1995; 2: 120-128. 18. Katzberg RW, et al. Acute cervical spine injuries: prospective MR imaging assessment at a level 1 . Radiology 1999; 213: 203-212. (Prospective study 199 patients – Level II/III evidence) 19. Benzel EC, Hart BL, Ball PA, et al. Magnetic resonance imaging for the evaluation of patients with occult cervical spine injury. J Neurosurg 1996; 85: 824-829. (Prospective study 174 consecutive patients – Level III evidence) 20. Flanders AE, Spetell Cm, Friedman DP, et al. The relationship between the functional abilities of patients with cervical spinal cord injury and the severity of damage revealed by MR imaging. AJNR 1999; 20: 926-934. (Retrospective study 49 patients – Level III evidence)

Further Reading 1. Blackmore CC, Mann FA, Wilson AJ, et al. Helical CT in the primary trauma evaluation of the cervical spine: an evidence-based approach. Skeletal Radiology 2000; 29: 632-639. 2. Takhtani D, Melham ER. MR imaging in cervical spine trauma. MRI Clin N America 2000; 8: 615-633.

238 SUSPECTED AVASCULAR NECROSIS

PLAIN RADIOGRAPHS • Initial study of choice for suspected avascular necrosis. 1 • When standard radiographs demonstrate the classic changes of osteonecrosis (crescent sign or articular collapse) further diagnostic imaging is unwarranted. 2 • Advantages: inexpensive and readily available. • Limitations: insensitive for detecting early changes. 3

THREE-PHASE BONE SCAN • Superior to plain radiographs but inferior to MRI for early detection of avascular necrosis. 3, 4 • ~75% sensitivity and specificity for avascular necrosis. 5, 6 • Useful screening modality if the site of pathology has not been localised. • Improved accuracy with the addition of SPECT. 7 • Limitations: • Poor spatial resolution. • Lacks specificity. 5

MAGNETIC RESONANCE IMAGING • Most accurate imaging modality for detection and staging of suspected avascular necrosis. 3, 5, 6, 8, 9 • Indicated in patients with clinically suspected radiographically occult avascular necrosis. 1 • 88-100% sensitivity and 72-87% specificity for detection of avascular necrosis. 3, 6, 8, 10

239 • Advantages: • Ability to detect bone marrow changes, including inflammatory and reactive hyperaemic changes, enables early detection of disease. 4 • Offers more specific diagnosis in patients with hip pain of uncertain aetiology. 11 • Allows assessment of the lesion size and location, which are shown to relate to prognosis and need for treatment. 12, 13 • Superior soft tissue contrast. • Mutiplanar imaging. • Limitations: expensive and limited availability. • Recent studies are evaluating the use of limited MRI examination for its time and cost saving potential. 14

240 REFERENCES 1. Bluemke DA, Zerhouni EA. MRI of avascular necrosis of bone. Topics in Magnetic Resonance Imaging 1996; 8(4): 231-246. 2. Froberg PK, Braunstein EM, Buckwalter KA. Osteonecrosis, transient osteoporosis, and transient bone marrow edema: current concepts. Radiol Clinics North America 1996; 34(2): 273-291. 3. Lee MJ, Corrigan J, Stack JP, et al. A comparison of modern imaging modalities in osteonecrosis of the femoral head. Clin Radiol 1990; 42: 427-432. (Prospective study 18 patients – Level III evidence) 4. Coleman BG, Kressel HY, Dalinka MK, et al. Radiographically negative avascular necrosis: detection with MR imaging. Radiology 1988; 168: 525-528. (Retrospective study 24 consecutive patients/case controls – Level IV evidence) 5. Beltran J, Herman LJ, Burk JM, et al. Femoral head avascular necrosis: MR imaging with clinical-pathologic and radionuclide correlation. Radiology 1988; 166: 215- 220. (Retrospective cohort of 49 patients / 85 hips – Level II evidence) 6. Markisz JA, Knowles RJ, Altchek DW, et al. Segmental patterns of avascular necrosis of the femoral heads: early detection with MR imaging. Radiology 1987; 162: 717-720. (Cohort of 64 hips – Level III evidence) 7. Kim KY, Lee SH, Moon DH, et al. The diagnostic value of triple head single photon emission computed tomography (3H-SPECT) in avascular necrosis of the femoral head. Int Orthop 1993; 17: 132-138. (Prospective study cohort of 32 patients – Level II/III evidence) 8. Mitchell MD, Kundel HL, Steinberg ME, et al. Avascular necrosis of the hip: comparison of MR, CT and scintigraphy. AJR 1986; 147: 67-71. (Level II/III evidence) 9. Mitchell DG, Rao VM, Dalinka MK, et al. Femoral head necrosis: correlation of MR imaging, radiographic staging, radionuclide imaging, and clinical findings. Radiology 1987; 162: 709-715. (Retrospective study 56 case controls – Level IV evidence) 10. Thickman D, Axel L, Kressel HY, et al. Magnetic resonance imaging of avascular necrosis of the femoral head. Skeletal Radiol 1986; 15: 133-140. (Retrospective study cohort of 45 consecutive patients/ 90 hips – Level II/III evidence) 11. Glickstein MF, Burk DL Jr, Schiebler ML, et al. Avascular necrosis versus other diseases of the hip: sensitivity of MR imaging. Radiology 1988; 169: 213-215. (Retrospective study 45 patients with hip pain and 10 normal controls – Level III evidence) 12. Lafforgue P, Dahan E, Chagnaud C, et al. Early stage avascular necrosis of the femoral head: MR imaging for prognosis in 31 cases with at least 2 years of follow- up. Radiology 1993; 187: 199-204. (Prospective study - Level II/III evidence) 13. Steinberg ME, Hayken GD, Steinberg DR. A quantitative system for staging avascular necrosis. J Bone & J Surg (Br) 1995; 77: 34-41. (Prospective study 100 hips – Level II/III evidence) 14. Khanna AJ, Yoon TR, Mont MA, et al. Femoral head osteonecrosis: detection and grading by using a rapid MR imaging protocol. Radiology 2000; 217: 188-192. (Prospective study 92 patients / 179 hips – Level II/III evidence)

Further Reading 1. Imhof H, Breitenseher M, Trattnig S, et al. Imaging of avascular necrosis of bone. European Radiology 1997; 7: 180-186. (Review)

241 SUSPECTED SCAPHOID FRACTURE

PLAIN RADIOGRAPHS • Screening method of choice for evaluating clinically suspected scaphoid fracture. 1-3 • Standard four view series (PA, Lateral, PA with ulnar deviation & obliques) are recommended. 1-3 • Up to 25% scaphoid fractures can be missed on plain radiographs. 4 • Standard practice in patients with clinically suspected scaphoid fractures but normal initial radiographs is to apply a cast and repeat radiographs in 10-14 days, when resorption at the fracture line should make previously occult fractures visible. 5, 6 • Some institutions advocate early use of bone scan/CT/MRI when initial radiographs are normal to avoid unnecessary immobilisation of wrist in plaster cast. 7, 8

BONE SCAN • Second line investigation for continuing clinical suspicion of scaphoid fracture when repeat radiographs are non-diagnostic. 1-3, 9 • A normal bone scan practically excludes a fractured scaphoid, but a positive scan is only 92% specific. 4, 10

COMPUTED TOMOGRAPHY • Indicated when repeat clinical and radiographic examinations are inconclusive. 1-3 • Useful in: 1. Detection of occult fractures of the wrist and displacement of fractures. 11 2. Determining the location and direction of the displaced carpal bones in complicated fracture-dislocations. 12 3. Assessment of union/nonunion and avascular necrosis. 13 MAGNETIC RESONANCE IMAGING • Indicated when repeat clinical and radiographic examinations are inconclusive. 1-3 • High accuracy for detection of radiographically occult fractures. 14-17

242 • Gadolinium-enhanced MRI can be used to evaluate vascularity of the proximal pole in scaphoid non-unions. 18 • Advantages: no ionising radiation, superior soft tissue detail, and can demonstrate marrow abnormalities (such as avascular necrosis, bone marrow oedema). • Disadvantages: expensive and limited availability.

243 REFERENCES 1. Plancher KD. Methods of imaging the scaphoid. Hand Clinics 2001; 17(4): 703-721. 2. Gilbert TJ, Cohen M. Imaging of acute injuries to the wrist and hand. Radiol Clin of North America 1997; 35(3): 701-725. 3. Munk PL, Lee MJ, Logan PM, et al. Scaphoid bone waist fractures, acute and chronic: imaging with different techniques. AJR 1997; 168: 779-786. (Review) 4. Tiel-van Buul MMC, Beek EJR, Broekhuizen AH, et al. Radiography and scintigraphy of suspected scaphoid fracture: a long-term study in 160 patients. J Bone Joint Surg 1993; 75-B: 61-65. (Prospective study 160 patients – Level II evidence) 5. Munk B, Frokjaer J, larsen CF, et al. Diagnosis of scaphoid fractures: a prospective multicenter study of 1,052 patients with 160 fractures. Acta Orthop Scand 1995; 66(4): 359-360. (Level II evidence) 6. Larsen CF, Brondum V, Wienholtz G, et al. An algorithm for acute wrist trauma: a systematic approach to diagnosis. J Hand Surg (Br) 1993; 18B: 207-212. (Prospective study 641 patients – Level II evidence) 7. Tiel-van Buul MM, Broekhuizen TH, van Beek EJ, et al. Choosing a strategy for the diagnostic management of suspected scaphoid fracture: a cost-effectiveness analysis. J Nucl Med 1995; 36(1): 45-48. (Level III evidence) 8. Dorsay TA, Major NM, Helms CA. Cost-effectiveness of immediate MR imaging versus traditional follow-up for revealing radiographically occult scaphoid fractures. AJR 2001; 177: 1257-1263. (Level III evidence) 9. Bayer LR, Widding A, Diemer H. Fifteen minutes bone scintigraphy in patients with clinically suspected scaphoid fracture and normal X-rays. Injury 2000; 31: 243-248. (Retrospective cohort of 52 consecutive patients – Level II/III evidence) 10. Murphy DG, Eisenhauer MA, Powe J, et al. Can a day 4 bone scan accurately determine the presence or absence of scaphoid fracture? Ann Emerg Med 1995; 26(4): 434-438. (Prospective study 99 patients – Level II evidence) 11. Hindman BW, Kulik WJ, Lee G, et al. Occult fractures of the carpal and metacarpals: demonstration with CT. AJR 1989; 153: 529-532. (Retrospective study cohort of 16 patients – Level III/IV evidence) 12. Nakamura R, Imaeda T, Horii E, et al. Analysis of scaphoid fracture displacement by three-dimensional computed tomography. J Hand Surg 1991; 16A: 485-492. (Cohort of 25 patients – Level III/IV evidence) 13. Hidaka Y, Nakamura R. Progressive patterns of degenerative arthritis in scaphoid nonunion demonstrated by three-dimensional computed tomography. J Hand Surg 1998; 23B: 765-770. (Cohort of 28 patients – Level III evidence) 14. Hunter JC, Escobedo EM, Wilson AJ, et al. MR imaging of clinically suspected scaphoid fractures. AJR 1997; 168: 1287-1293. (Prospective study 36 consecutive patients – Level II/III evidence) 15. Breitenseher MJ, Metz VM, Gilula LA, et al. Radiographically occult scaphoid fractures: value of MR imaging in detection. Radiology 1997; 203: 245-250. (Prospective study 42 consecutive patients – Level II/III evidence) 16. Raby N. Magnetic resonance imaging of suspected scaphoid fractures using low field dedicated extremity MR system. Clin Radiology 2001; 56: 316-320. (Prospective study 99 patients – Level III evidence) 17. Fowler C, Sullivan B, Williams LA, et al. A comparison of bone scintigraphy and MRI in the early diagnosis of the occult scaphoid waist fracture. Skeletal Radiology 1998; 27: 683-687. (Prospective study 43 patients – Level III evidence) 18. Cerezal L, Abascal F, Cang A, et al. Usefulness of gadolinium-enhanced MR imaging in the vascularity in the evaluation of the vascularity of scaphoid

244 nonunions. AJR 2000; 174: 141-149. (Prospective study 37 consecutive patients – Level II/III evidence)

Further Reading 1. Krasin E, Goldwirth M, Gold A, et al. Review of the current methods in the diagnosis and treatment of scaphoid fractures. Postgrad Med J 2001; 77: 235-237.

245 SUSPECTED STRESS FRACTURE

PLAIN RADIOGRAPHS • Initial imaging modality of choice for the detection of suspected stress fractures. 1 • Plain film diagnosis of stress fracture depends on the site of injury and the temporal relationship of imaging to the stage of osteoclastic resorption, osteoblastic repair, and/or periosteal new bone formation. 2 • Most stress fractures are oriented transversely to the bone, but occasionally longitudinal stress fractures are encountered. 1 • In cases, where plain films demonstrate changes consistent with stress fracture, such as linear cortical radiolucency or localised periosteal reaction, no further imaging is indicated. 3 • Early radiographs are often normal, as plain radiography is insensitive in detection of the early phases of stress remodelling. 1, 3, 4 • If the plain radiographs are normal or nondiagnostic, the physician may choose to treat the patient for a presumed fracture and repeat the studies within 6 weeks or further investigate with CT/MRI or bone scan. 3 • Advantages: inexpensive and widely available

THREE-PHASE BONE SCAN • Second line study for the detection of radiographically occult stress fractures. 5 • High sensitivity (~100%) for stress fractures and can become positive as early as three days after the onset of clinical symptoms. 4-6 • A normal bone scan generally excludes the diagnosis of stress/insufficiency fracture. • Classical findings include focally intense and fusiform cortical uptake. 1 • Offers physiological information from which both the age of the injury as well as the status of healing of the fracture can be inferred. 7

246 • Limitations: lacks specificity (false positives can occur in osteoid osteoma, osteomyelitis, or metastatic disease) and supplemental imaging (CT/MRI) may be necessary for conclusive diagnosis or to avoid false positives. 1

MAGNETIC RESONANCE IMAGING • Comparable sensitivity but superior specificity to that of bone scan for detection of bone abnormalities. 8, 9 • Allows depiction of abnormalities several weeks prior to the development of radiographic changes. 7, 8 • For detection of hip fracture, can be performed immediately upon patient presentation. 8-10 • Can be used in cases suspected stress fractures where radiographic +/- bone scan findings are indeterminate. 1, 10 • Useful in grading the stage of certain stress fractures and therefore, predicting the time to recovery (superior spatial resolution allows determination of the extent and orientation of the osseous fracture). 7, 11, 12 • Limitations: expensive and limited availability.

COMPUTED TOMOGRAPHY • Provides superior depiction of the osseous anatomy of stress fractures. 1, 13 • Useful in: 1, 13 1. Delineation of fracture in a “high-risk” location. 2. Demonstrating the fracture line in a longitudinally directed injury, which is often not imaged well with MRI. 3. Demonstrating pelvic and sacral fractures in the elderly. 4. Evaluating healing when the plain radiographs do not adequately demonstrate the fracture. • Limitations: may not detect soft tissue or medullary lesions.

247 REFERENCES 1. Anderson MW, Greenspan A. Stress fractures. Radiology 1996; 199: 1-12. (Review) 2. Umans H, Pavlov H. Stress fractures of the lower extremities. Seminars in Roentgenology 1994; XXIX (2): 176-193. (Review) 3. Daffner RH, Pavalov H. Stress fractures: current concepts. AJR 1992; 159: 245-252. (Review) 4. Courtenay BG, Bowers DM. Stress fractures: clinical features and investigation. MJA 1990; 153: 155-156. (Retrospective study 92 case controls with stress fractures – Level IV evidence) 5. Shikare S, Samsi AB, Tilve GH. Bone imaging in sports medicine. J Postgraduate Medicine 1997; 43(3): 71-72. (Cohort of 20 patients – Level III evidence) 6. Matin P. The appearance of bone scans following fractures, including immediate and long-term studies. J Nucl Med 1979; 20(12): 1227-1231. (Prospective study 204 patients – Level II evidence) 7. Deutsch AL, Coel MN, Mink JH. Imaging of stress injuries to bone: radiography, scintigraphy, and MR imaging. Clinics in Sports Medicine 1997; 16(2): 275-290. (review) 8. Shin AY, Morin WD, Gorman J, et al. The superiority of magnetic resonance imaging in differentiating the cause of hip pain in endurance athletes. Am J Sports Med 1996; 24(2): 168-176. (Prospective study 19 subjects – Level II/III evidence) 9. Rizzo PF, Gould ES, Lyden JP, et al. Diagnosis of occult fractures about the hip: magnetic resonance imaging compared with bone scanning. J Bone & J Surg 1993; 75-A (3): 395-401. (Prospective study 62 consecutive patients – Level II evidence) 10. Deutsch AL, Mink JH, Waxman AD. Occult fractures of proximal femur: MR imaging. Radiology 1989; 170: 113-116. (Prospective study 23 patients – Level III evidence) 11. Fredericson M, Bergman AG, Hoffman KL, et al. Tibial stress reaction in runners: correlation of clinical symptoms and scintigraphy with a new magnetic resonance imaging grading system. Am J Sports Med 1995; 23: 472-481. (Cohort of 18 symptomatic legs – Level III evidence) 12. Yao L, Johnson C, Gentili A, et al. Stress injuries of bone: analysis of MR imaging staging criteria. Acad Radiol 1998; 5: 34-40. (Cohort of study 35 patients – Level III evidence) 13. Shearman CM, Brandser EA, Parman LM, et al. Longitudinal tibial fractures: a report of eight cases and review of literature. J Comput Assist Tomogr 1998; 22(2): 265-269. (Retrospective study 8 case controls- Level IV evidence)

Further Reading 1. Greenspan A. Evaluating suspected stress fracture. Journal of Musculoskeletal Medicine 1999; 16: 144.

248 FIRST TRIMESTER BLEEDING

ULTRASOUND IN FIRST TRIMESTER OF PREGNANCY • Routine US examination is not recommended in first trimester. 1 • Indications for ultrasound in the first trimester of pregnancy include: 2-5 1. Assessment of gestational age and sac. 2. Detection of early pregnancy failure. 3. Assessment of fetal number. 5 4. Detection of fetal abnormalities. 5. Nuchal translucency. 6. Assessment of ovaries, uterus and adnexa.

TRANSABDOMINAL ULTRASONOGRAPHY (US) • Useful screening test for early pregnancy complications such as threatened abortion, ectopic pregnancy, blighted ovum, trophoblastic disease etc. 6,7

249 • Correlation of sonographic findings with simultaneous maternal serum human chorionic gonadotropin (β-HCG) levels is useful in evaluation of early pregnancy complications, particularly when a living embryo is not visualised. 7,8 • Allows identification of an intrauterine pregnancy, which is the single most important finding for the exclusion of ectopic gestation as the presence of both intra- and extra-uterine pregnancy, is very rare. 7 • Enables examination of fetal anatomy and measurement of nuchal translucency, thus allowing detection of majority of fetal structural and chromosomal abnormalities in early pregnancy. 9-11 • Allows assessment of the outcome of early first-trimester with slow embryonic heart rates (embryonic heart rate of <70bpm is associated with fetal demise in 100% of patients; and if the embryonic heart rate is <90bpm in the first trimester, close follow-up of the pregnancy is recommended). 12 • Follow-up second trimester US still be required as a supplement, whether the first trimester US shows normal or abnormal viable intrauterine pregnancy as significant abnormalities such as heart and spinal defects can still be missed on first trimester US. 9

ENDOVAGINAL ULTRASONOGRAPHY • More sensitive than transabdominal ultrasonography and has a lower discriminatory zone (the range of serum concentrations above which gestational sac can be visualised consistently), allowing earlier diagnoses of intrauterine or ectopic pregnancies. 8, 13-15 • Superior to transabdominal US for visualising fetal anatomy and detecting fetal structural and chromosomal abnormalities. 10, 11, 16 • The normal intrauterine pregnancy is visible transvaginally by approximately 5 weeks from the first day of the last menstrual period. 2,3 • With regards to suspected ectopic pregnancy, patients with indeterminate ultrasonographic findings (ie. no evidence of intrauterine or ectopic pregnancy) require further evaluation with quantitative β-hCG levels +/- follow-up US or laparoscopy. 14, 17-19

SERUM HUMAN CHORIONIC GONADOTROPHIN (β-hCG) LEVELS • Serum β-hCG levels double approximately every 48 hours in 85% of normal intrauterine pregnancies of between 4 and 6 weeks’ gestation. 19 • >80% of ectopic pregnancies are associated with a rise in β-hCG of less than 66%. 18,19 • Levels of 1000-1500 iu/l should be associated with the presence of an intrauterine gestation on transvaginal US (6000-6500 iu/l for transabdominal), although in multiple pregnancy this level may be higher. 8 • Levels of more than 1000 iu/l with no gestation sac can also be seen following spontaneous abortion, emphasising the need to interpret single β-hCG measurements in the context of the clinical history and findings. 19

250 REFERENCES 1. Ewigman B, LeFevre M, Hesser J. A randomized trial of routine prenatal ultrasound. Obstetrics and Gynaecology 1990; 76: 189-194. 2. Estroff JA. Emergency obstetric and gynecologic ultrasound. Radiol Clin North Am 1997; 35: 921-957. 3. Sohaey R, Woodward P, Zwiebel WJ. First-trimester ultrasound: the essentials. Seminars in US, CT, and MRI 1996; 17(1): 2-14. 4. Australasian Society for Ultrasound in Medicine. Guidelines for the performance of first trimester ultrasound. ASUM guidelines, October 1999. 5. Snijders R. First trimester ultrasound. Clinics in Perinatology 2001; 28(2): 333-352. 6. Wong TW, Lau CC, Yeung A, et al. Efficacy of transabdominal ultrasound examination in the diagnosis of early pregnancy complications in an emergency department. J Accid Emerg Med 1998; 15: 155-158. (Prospective study 151 pregnant women with abdominal pain and/or vaginal bleeding – Level II evidence) 7. Braffman BH, Coleman BG, Ramchandani P, et al. Emergency department screening for ectopic pregnancy: a prospective US study. Radiology 1994; 190: 797- 802. (Prospective study cohort of 1427 patients – Level II evidence) 8. Nyberg DA, Mack LA, Laing FC, et al. Early pregnancy complications: endovaginal sonographic findings correlated with human chorionic gonadotropin levels. Radiology 1988; 167: 619-622. (Prospective study 84 patients – Level III evidence) 9. Whitlow BJ, Chatzopapas IK, Lazanakis ML, et al. The value of sonography in early pregnancy for detection of fetal abnormalities in an unselected population. Br J Obstet & Gynaecol 1999; 106: 929-936. (Prospective cross-sectional study 6634 pregnant women – Level II evidence) 10. Braithwaite JM, Armstrong MA, Economides DL. The assessment of fetal anatomy at 12-13 weeks using transabdominal and transvaginal sonography. Br J Obstet Gynaecol 1996; 103: 82-85. (Cohort of 298 women – Level II evidence) 11. Economides DL, Whitlow BJ, Braithwaite JM, et al. Ultrasonography in the detection of fetal anomalies in early pregnancy. Br J Obstet Gynaecol 1999; 106: 516-523. (Review) 12. Benson CB, Doubilet PM. Slow embryonic heart rate in early first trimester: indicator of poor pregnancy outcome. Radiology 1994; 192: 343-344. (Retrospective study 40 patients – Level III evidence) 13. Jain KA, Hamper UM, Sanders RC. Comparison of transvaginal and transabdominal sonography in the detection of early pregnancy and its complications. AJR 1988; 151: 1139-1143. (Cohort of 90 patients – Level III evidence) 14. Barnhart K, Mennuti MT, Benjamin I, et al. Prompt diagnosis of ectopic pregnancy in an emergency department setting. Obstet Gynecol 1994; 84: 1010-1015. (Prospective study 1263 patients – Level II evidence) 15. Cacciatore B, Stenman UH, Ylostalo P. Diagnosis of ectopic pregnancy by vaginal ultrasonography in combination with a discriminatory serum hCG level of 1000 IU/l [IRP]. Br J Obstet Gynaecol 1990; 97: 904-908. (Prospective study 200 consecutive patients – Level II evidence) 16. Economides DL, Whitlow BJ, Kadir R, et al. First trimester sonographic detection of chromosomal abnormailites in an unselected population. Br J Obstet Gynaecol 1998; 105: 58-62. (Largest study 96,127 women – Level II evidence) 17. Dart RG, Burke G, Dart L. Subclassification of indeterminate pelvic ultrasonography: prospective evaluation of the risk of ectopic pregnancy. Ann Emer Med 2002; 39: 382-388. (Prospective observational study 635 patients – Level II evidence)\ 18. Dart RG, Mitterando J, Dart LM. Rate of change of serial β-human chorionic gondaotropin values as a predictor of ectopic pregnancy in patients with

251 indeterminate transvaginal ultrasound findings. Ann Emerg Med 1999; 34: 703-710. (Retrospective study 381 patients – Level II evidence) 19. Symonds IM. Ectopic pregnancy: modern management. Current Obstetrics & Gynaecology 1998; 8: 27-31.

Further Reading 1. Dart RG. Role of pelvic ultrasonography in evaluation of symptomatic first- trimester pregnancy. Ann Emerg Med 1999; 33: 310-320. 2. Albayram F, Hamper UM. First trimester obstetric emergencies: spectrum of sonographic findings. J Clin Ultrasound 2002; 30(3): 161-177.

252 PELVIMETRY

• Traditionally, conventional plain X-Ray pelvimetry (up to three views) has been the standard to provide an anatomical and quantitative assessment of the maternal pelvis. Nowadays, low dose CT pelvimetry is the preferred method for assessing the dimensions of maternal pelvis. 1 • Examination comprises of: 1 1. Lateral scanogram (topogram) 2. AP scanogram 3. Single axial slice through the level of the ischial spines • Measurements include: 1 1. AP diameters (conjugate) • pelvic inlet (true or obstetric conjugate) • mid pelvis • pelvic outlet 2. Transverse diameters • bi-ischial (interspinous) diameter • inlet • intertuberous (outlet) • Indications: 1 1. Ante-partum: • Abnormal progress of labour • Abnormal fetal presentation • Suspected cephalo-pelvic disproportion 2. Post-partum: previous Caesarean section. • Abnormal measurements do not necessarily exclude vaginal delivery. 2, 3 • Normal measurements cannot predict safe vaginal delivery due to possible “soft- tissue dystocia”. 3 • Information derived is supplemental to the clinical decision to initiate, continue, or terminate a trial of labour. 1, 3 • Fetal-pelvic index calculated by combination of fetal ultrasound (for estimates of fetal size) and digital radiography (for maternal pelvic measurements) is moderately predictive of fetal-pelvic disproportion. 4 • Advantages: • Lower radiation dose (further reduction in radiation dose with digital radiography technique). 5-7 • Wider availability compared to MRI. • MRI pelvimetry may have a greater role in the future as it becomes more widely available. 8, 9

253 REFERENCES 1. Ferguson JE II, Sistrom CL. Can fetal-pelvic disproportion be predicted. Clinical Obstet Gynecol 2000; 43(2): 247-264. (Review) 2. Krishnamurthy S, Fairlie F, Cameron AD, et al. The role of postnatal X-Ray pelvimetry after caesarean section in the management of subsequent delivery. Br J Obstet Gynaecol 1991; 98: 716-718. (Retrospective study 331 women – Level III evidence) 3. Thubisi M, Ebrahim A, Moodley J, et al. Vaginal delivery after previous caesarean section: is X-Ray pelvimetry necessary? Br J Obstet Gynaecol 1993; 100: 421-424. (Prospective controlled trial 306 women – Level II evidence) 4. Ferguson II JE, Newberry YG, DeAngelis GA, et al. The fetal-pelvic index has minimal utility in predicting fetal pelvic disproportion. Am J Obstet Gynecol 1998; 179: 1186-1192. (Prospective study 91 patients – Level III evidence) 5. Federle MP, Cohen HA, Rosenwein MF, et al. Pelvimetry by digital radiography: a low-dose examination. Radiology 1982; 143: 733-735. 6. Wright DJ, Godding L, Kirkpatrick C. Technical note: digital radiographic pelvimetry – novel, low dose, accurate technique. Br J Radiology 1995; 68: 528- 530. (Level III evidence) 7. Ferguson JE II, DeAngelis GA, Newberry YG, et al. Fetal radiation exposure is minimal after pelvimetry by modified digital radiography. Am J Obstet Gynecol 1996; 175: 260-269. (Prospective study 29 patients – Level III evidence) 8. Van Loon AJ, Mantingh A, Serlier EK, et al. Randomised controlled trial of magnetic resonance pelvimetry in breech presentation at term. Lancet 1997; 350: 1799-1804. (Prospective randomised controlled study 235 patients – Level II evidence) 9. Sporri S, Hanggi W, Braghetti A, et al. Pelvimetry by magnetic resonance imaging as a diagnostic tool to evaluate dystocia. Obstet Gynecol 1997; 89: 902-908. (Retrospective study cohort of 42 patients – Level III evidence)

254 SUSPECTED ECTOPIC PREGNANCY

ECTOPIC PREGNANCY • Clinical diagnosis may be difficult as classical features of pain, vaginal bleeding and an adnexal mass/tenderness may not be reliable. 1, 2

TRANSABDOMINAL +/- ENDOVAGINAL ULTRASONOGRAPHY • Pelvic ultrasonography (transabdominal US +/- endovaginal US) combined with measurement of serum β-hCG levels, is an effective screening strategy for diagnosing ectopic pregnancy. 3-6 • Allows identification of an intrauterine pregnancy, which is the single most important finding for the exclusion of ectopic gestation as the presence of both intra- and extra-uterine pregnancy, is very rare. 1, 3-6 • Compared to transabdominal ultrasonography, transvaginal ultrasonography is more sensitive and has a lower discriminatory zone (the range of serum β-hCG

255 concentrations above which gestational sac can be visualised consistently). This allows earlier diagnoses of intrauterine or ectopic pregnancies. 7-11 • Sensitivity for transvaginal ultrasonography ranges from 69 to 96% and specificity from 84 to 99%. 1, 3, 9, 12 • When used in conjunction with serum β-hCG levels, transvaginal ultrasound has comparable sensitivity and specificity for ectopic pregnancy to laparoscopy. 13 • Presence of an adnexal mass and/or free pelvic fluid is strong predictor of an ectopic pregnancy. 10, 14-17 • Findings suggestive of ectopic pregnancy include: 13 1. Fluid in the pouch of Douglas, an adnexal mass and an empty uterus. 2. An adnexal mass, empty uterus or pseudogestational sac and a positive β-hCG. 3. Direct demonstration of ectopic fetus and fetal heart. • Normal US does not exclude the diagnosis of ectopic pregnancy. 3, 14, 15 • Patients with indeterminate ultrasonography findings require further evaluation with quantitative β-hCG levels +/- follow-up US or laparoscopy as about 15-20% of these patients will have a final diagnosis of ectopic pregnancy. 18, 19

SERUM HUMAN CHORIONIC GONADOTROPHIN (β-hCG) LEVELS • Serum β-hCG levels double approximately every 48 hours in 85% of normal intrauterine pregnancies of between 4 and 6 weeks’ gestation. 20 • >80% of ectopic pregnancies are associated with a rise in β-hCG of less than 66%. 19, 20 • Levels of 1000-1500iu/l should be associated with the presence of an intrauterine gestation on transvaginal US (6000-6500 iu/l for transabdominal), although in multiple pregnancy this level may be higher. 8

256 REFERENCES 1. Kaplan BC, Dart RG, Moskos M, et al. Ectopic pregnancy: prospective study with improved diagnostic accuracy. Ann Emerg Med 1996; 28: 10-17. (Prospective study 481 consecutive patients – Level II evidence) 2. Abbott JT, Emmans LS, Lowenstein SR: Ectopic pregnancy: Ten common pitfalls in diagnosis. Am J Emerg Med 1990; 8: 515-522. (Retrospective study 65 case controls – Level IV evidence) 3. Braffman BH, Coleman BG, Ramchandani P, et al. Emergency department screening for ectopic pregnancy: a prospective US study. Radiology 1994; 190: 797- 802. (Prospective study cohort of 1427 patients – Level II evidence) 4. Barnhart K, Mennuti MT, Benjamin I, et al. Prompt diagnosis of ectopic pregnancy in an emergency department setting. Obstet Gynecol 1994; 84: 1010-1015. (Prospective study 1263 patients – Level II evidence) 5. Gracia CR, Barnhart KT. Diagnosing ectopic pregnancy: decision analysis comparing six strategies. Obstet Gynecol 2001; 97:464-470. (Level II evidence) 6. Wong TW, Lau CC, Yeung A, et al. Efficacy of transabdominal ultrasound examination in the diagnosis of early pregnancy complications in an emergency department. J Accid Emerg Med 1998; 15: 155-158. (Prospective study 151 patients – Level II evidence) 7. Jain KA, Hamper UM, Sanders RC. Comparison of transvaginal and transabdominal sonography in the detection of early pregnancy and its complications. AJR 1988; 151: 1139-1143. (Cohort of 90 patients – Level III evidence) 8. Nyberg DA, Mack LA, Laing FC, et al. Early pregnancy complications: endovaginal sonographic findings correlated with human chorionic gonadotropin levels. Radiology 1988; 167: 619-622. (Prospective study 84 patients – Level III evidence) 9. Nyberg DA, mack LA, Jeffery RB Jr, et al. Endovaginal sonographic evaluation of ectopic pregnancy: A prospective study. AJR 1987; 149: 1181-1186. (Prospective study 84 patients – Level III evidence) 10. Cacciatore B, Stenman UH, Ylostalo P. Diagnosis of ectopic pregnancy by vaginal ultrasonography in combination with a discriminatory serum hCG level of 1000 IU/l [IRP]. Br J Obstet Gynaecol 1990; 97: 904-908. (Prospective study 200 consecutive patients – Level II evidence) 11. Cacciatore B, Stenman UH, Ylostalo P, et al. Comparison of abdominal and vaginal sonography in suspected ectopic pregnancy. Obstet Gynecol 1989; 73: 770-774. (Prospective study 100 patients – Level III evidence) 12. Timor-Tritch IA, Yeh MN, Peisner DB, et al. The use of transvaginal ultrasonography in the diagnosis of ectopic pregnancy. Am J Obst Gynecol 1989; 161: 157-161. (Cohort of 147 patients – Level III evidence) 13. Sadek AL, Schiotz HA. Transvaginal sonography in the management of ectopic pregnancy. Acta Obstet Gynecol Scand 1995; 74: 293-296. (Prospective study 525 consecutive patients – Level II evidence) 14. Brown DL, Doubilet PM. Transvaginal sonography for diagnosing ectopic pregnancy: Positivity criteria and performance characteristics. J Ultrasound Med 1994; 13: 259-266. (Analysis of 10 studies with total of 2216 patients – Level II evidence) 15. Russell SA, filly RA, Damato N. Sonographic diagnosis of ectopic pregnancy with endovaginal probes: what really has changed? J Ultrasound Med 1993; 3: 145-151. (Retrospective study cohort of 123 patients – Level III evidence) 16. Nyberg DA, Hughes MP, Mack LA, et al. Extrauterine findings of ectopic pregnancy at transvaginal US: importance of echogenic fluid. Radiology 1991; 178: 823-826. (Prospective study cohort of 232 patients – Level II evidence)

257 17. Cacciatore B. Can the status of tubal pregnancy be predicted with transvaginal sonography? A prospective comparison of sonographic, surgical and serum hCG findings. Radiology 1990; 177: 481-484. (Prospective study cohort of 120 patients – Level II evidence) 18. Dart RG, Burke G, Dart L. Subclassification of indeterminate pelvic ultrasonography: prospective evaluation of the risk of ectopic pregnancy. Ann Emer Med 2002; 39: 382-388. (Prospective observational study 635 patients – Level II evidence) 19. Dart RG, Mitterando J, Dart LM. Rate of change of serial β-human chorionic gondaotropin values as a predictor of ectopic pregnancy in patients with indeterminate transvaginal ultrasound findings. Ann Emerg Med 1999; 34: 703-710. (Retrospective study 381 patients – Level II evidence) 20. Symonds IM. Ectopic pregnancy: modern management. Current Obstetrics & Gynaecology 1998; 8: 27-31.

Further Reading 1. Dart RG. Role of pelvic ultrasonography in evaluation of symptomatic first- trimester pregnancy. Ann Emerg Med 1999; 33: 310-320. 2. Frates MC, Laing FC. Sonographic evaluation of ectopic pregnancy: an update. AJR 1995; 165: 251-259. (Review) 3. Durston WE, Carl ML, Guerra W, et al. Ultrasound availability in the evaluation of ectopic pregnancy in the ED: comparison of quality and cost-effectiveness with different approaches. Am J Emerg Med 2000; 18: 408-417.

258 THIRD TRIMESTER OF PREGNANCY

Indications for ultrasound in the third trimester of pregnancy include: 1, 2 Fetal well-being • Fetal number, presentation and lie • Fetal cardiac activity • Measurements of fetal size • Large-for-dates - multiple pregnancy; wrong dates; uterine / ovarian masses; hydatidiform mole; polyhydramnios • Small-for-dates - wrong dates; fetal death; intrauterine growth retardation; oligohydramnios; pseudocyesis • Fetal anatomy • Placental site or localisation • Amniotic fluid volume • Maternal disease eg. hypertension, diabetes, infection etc Measurements include biparietal diameter, head circumference, abdominal circumference, femur length, and estimation of fetal weight. • Biophysical profile includes fetal heart rate, breathing, movements, tone, amniotic fluid and systolic/diastolic ratio in the umbilical artery.

Pain or bleeding • Placental abruption • Placenta praevia – major, marginal (repeat US at 32 weeks) • Premature rupture of membranes • Detection and evaluation of maternal pelvic or adnexal masses

Caution: dates must not be changed based on third trimester scan unless the patient has no idea about their dates and this is the only scan.

REFERENCES 1. Estroff JA. Emergency obstetric and gynecologic ultrasound. Radiologic Clinics of North America 1997; 35(4): 921-957. (Review) 2. Australasian Society for Ultrasound in Medicine (ASUM). Guidelines for the performance of third trimester ultrasound. ASUM guidelines October 1999.

259 BRONCHIECTASIS

BRONCHIECTASIS • Bronchiectasis is irreversible dilatation of the bronchial tree while bronchiolectasis is irreversible dilatation of peripheral airways. 1 • May result from obstruction, abnormal mucous production, infection, and/or congenital abnormalities of the bronchial wall. 1

PLAIN CHEST RADIOGRAPH (CXR) 1,2 • Initial investigation to exclude other causes for the patient’s symptoms. • Sensitivity (37-47%) and specificity 95% for diagnosing bronchiectasis when used as gold standard. 3,4 • More recent study reported 87% sensitivity and 74% specificity when plain radiographic findings were compared to HRCT. 5 • Radiographic manifestations are non-specific; positive findings include increased linear markings, crowding, cystic spaces and honeycombing. 1,2,6 • Limitations: 1-4 • Low specificity. • May be normal in mild disease. • Underestimates the severity and the extent of disease.

HIGH RESOLUTION COMPUTED TOMOGRAPHY (HRCT) • Imaging investigation of choice to identify and define the type and extent of bronchiectasis. 1,2,7 • High sensitivity of 84-95% and specificity of 93-100% for detection and determining the extent of bronchiectasis. 8-10 • CT appearances of bronchiectasis depend on the bronchiectatic pattern, as defined by Reid’s classification, and on the orientation of the bronchus in relation to the plane of scanning. 1 1. Cylindrical bronchiectasis is classified depending on a horizontal or vertical course of the bronchi in the scan plane as “tramlines” or “signet rings”. 2. Varicose bronchiectasis shows a greater degree of dilatation and the walls of the dilated bronchi assume a beaded appearance. 3. Cystic bronchiectasis can be recognised by air-fluid levels, strings, or cluster of cysts. • There is a significant linear relationship between the severity of bronchiectasis at HRCT and abnormalities as seen on the chest radiograph. 5

BRONCHOGRAPHY • Rarely performed these days. • Disadvantages: invasive procedure with a risk of complications.

260 REFERENCES 1. Tasker AD, Flower CDR. Imaging the airways: hemoptysis, bronchiectasis, and small airways disease. Clinics in Chest Medicine 1999; 20: 761-773. 2. Kumar NA, Nguyen B, Maki D. Bronchiectasis: current clinical and imaging concepts. Seminars in Roentgenology 2001; 36(1): 41-50. 3. Currie DC, Cooke JC, Morgan AD, et al. Interpretation of bronchograms and chest radiographs in patients with chronic sputum production. Thorax 1987; 42:278-284. (Cohort of 27 patients – Level III evidence) 4. Cooke JC, Currie DC, Morgan AD, et al. Role of computed tomography in diagnosis of bronchiectasis. Thorax 1987; 42: 272-277. (Cohort of 27 patients – Level III evidence) 5. Van der Bruggen-Bogaarts BAHA, Van der Bruggen HMJG, Van Waes PFGM, et al. Screening for bronchiectasis: a comparative study between chest radiography and high resolution CT. Chest 1996; 109: 608-611. (Prospective study cohort of 84 patients – Level II/III evidence) 6. Gudberg CE. Roentgenologic diagnosis of bronchiectasis: an analysis of 112 cases. Acta Radiol 1955; 195: 649-654. 7. Grenier P, Cordeau M-P, Biegelman C. High-resolution computed tomography of the airways. J Thorac Imaging 1993; 8: 213- 229. 8. Munro NC, Cooke JC, Currie DC, et al. Comparison of thin section computed tomography with bronchography for identifying bronchiectatic segments in patients with chronic sputum production. Thorax 1990; 45: 135-139. (Cohort of 27 patients – Level II/III evidence) 9. Kang EY, Miller RR, Muller NL. Bronchiectasis: comparison of preoperative thin- section CT and pathologic findings in resected specimens. Radiology 1995; 195: 649-654. (Retrospective study 22 consecutive patients – Level IV evidence) 10. Grenier P, Maurice F, Musset D, et al. Bronchiectasis: assessment by thin-section CT. Radiology 1986; 161: 95-99. (Cohort of 36 patients – Level III evidence)

261 HAEMOPTYSIS

PLAIN CHEST RADIOGRAPHS (CXR) • May detect a cause of haemoptysis in 40-50% of cases. 1,10 • Patients with negative CXR and 2 or more risk factors for malignancy (>50yrs old, >40pack year smoking history) for malignancy need to be further investigated. 1-4 • Patients with fewer than 2 risk factors for malignancy can be followed by observation. 1-4 COMPUTED TOMOGRAPHY (CT) • Most sensitive diagnostic test with a positive yield of 67%. 1,5,6 • Primary investigation in patients with normal or non-localising chest radiographs. 6,9

262 • Initial Chest CT before bronchoscopy in patients in whom the chest radiograph is abnormal or suggestive of malignancy is cost effective in improving diagnostic yield from invasive diagnostic procedures and in some cases, eliminates the need for any further investigation. 3,6,7 • Useful for: • Diagnosing peripheral airway disease, in particular, bronchiectasis, as well as radiographically occult parenchymal neoplasms. 3,6 • Staging of bronchogenic carcinoma. 8 • Guiding percutaneous needle biopsy. • Providing roadmap for both bronchial and transbronchial biopsy. • Limitations: insensitive to early mucosal abnormalities. 3,5

HIGH RESOLUTION CT (HRCT) • Investigation of choice for suspected bronchiectasis. 3

BRONCHOSCOPY • Allows biopsies to be taken for histology or brushings and washings for cytology and microbiology. 1-4 • Provides the option of therapeutic intervention. • Limitations: failure to visualise peripheral lesions. 3,5 • Disadvantages: invasive procedure with a risk of complications.

RIGID BRONCHOSCOPY • Urgent rigid bronchoscopy is indicated in unstable patients with massive haemoptysis because of its greater suctioning ability and maintenance of airway patency. 9,10 • Precedes bronchial angiography and embolisation to locate the bleeding site (sensitivity 67%). 1

BRONCHIAL ANGIOGRAPHY • Indicated when bronchial embolisation is intended. 9 • Angiographic signs of pulmonary haemorrhage include extravasation of contrast media, hypervascularisation, abnormal arborisation of bronchial arteries, systemic- pulmonary shunts and bronchial artery aneurysms.

BRONCHIAL ARTERY EMBOLISATION • Effective treatment adjunct to control bronchial bleeding and reduces the need for high-risk emergency lung resections (immediate control of bleeding in 75-93% of cases). 10-12 • Aims to reduce the systemic arterial perfusion pressures to the fragile vessels within inflammatory tissue and to try to prevent the development and enlargement of non- bronchial systemic arterial collaterals. 9 • Reserved for patients with life threatening haemoptysis. • Helps avoid surgery in patients who are not good surgical candidates. 11 • Limitations: 11,12 • 20% recurrence rate. • Potential complications include accidental embolisation of the spinal artery either by contrast material or the embolising particles causing ischaemic injury to the spinal cord. • 0-20% technical failure rate due to inability to cannulate the vessel, instability of the catheter tip, or visualisation of anterior spinal artery.

263 REFERENCES 1. Hirshberg B, Biran I, Glazer M, et al. Hemoptysis: etiology, evaluation, and outcome in a tertiary referral hospital. Chest 1997; 112: 440-444. (Retrospective study cohort 208 patients – Level II/III evidence) 2. Poe RH, Israel RH, Marin MG, et al. Utilization of fiberoptic bronchoscopy in patients with hemoptysis and a nonlocalizing chest roentgenogram. Chest 1988; 93(1): 70-75. (Retrospective study cohort 196 patients – Level II/III evidence) 3. McGuiness G, Beacher JR, Harkin TJ, et al. Hemoptysis: Prospective high- resolution CT/bronchoscopic correlation. Chest 1994; 105: 1155-1162. (Prospective study 57 consecutive patients – Level II/III evidence) 4. Lederle FA, Nichol KL, Parenti CM. Bronchoscopy to evaluate hemoptysis in older men with nonsuspicious chest roentgenograms. Chest 1989; 95: 1043-1047. (Retrospective study 106 patients – Level III evidence) 5. Set PAK, Flower CDR, Smith IE, et al. Hemoptysis: comparative study of the role of CT and fiberoptic bronchoscopy. Radiology 1993; 189: 677-680. (Prospective study 91 patients – Level II/III evidence) 6. Millar AB, Boothroyd AE, Edwards D, et al. The role of computed tomography (CT) in the investigation of unexplained hemoptysis. Respir Med 1992; 86(1): 39- 44. (Prospective study 40 patients – Level II/III evidence) 7. Laroche C, Fairbairn I, Moss H, et al. Role of computed tomographic scanning of the thorax prior to bronchoscopy in the investigation of suspected lung cancer. Thorax 2000; 55: 359-363. (Prospective randomised study 171 patients – Level II evidence) 8. Nadich DP, Funt S, Ettenger NA, et al. Hemoptysis: CT-bronchoscopic correlation in 58 cases. Radiology 1990; 177(2): 357-362. (Retrospective study cohort of 58 patients – Level II/III evidence) 9. Marshall TJ, Flower CDR, Jackson JE. The role of radiology in the investigation and management of patients with haemoptysis. Clinical Radiology 1996; 51: 391- 400. (Review) 10. Jean-Bapiste E. Clinical assessment and management of massive hemoptysis. Crit Care Med 2000; 28: 1642-1647. (Review) 11. Swanson KL, Johnson CM, Prakash UBS, et al. Bronchial Artery embolization: experience with 54 patients. Chest 2002; 121: 789-795. (Retrospective study 54 patients – Level III evidence) 12. Mal H, Rullon I, Mellot F, et al. Immediate and long-term results of bronchial artery embolisation for life threatening hemoptysis. Chest 1999; 115: 996-1001. (Retrospective study case series 56 consecutive patients – Level III evidence)

264 RAISED HEMIDIAPHRAGM ON CHEST RADIOGRAPH

RAISED HEMIDIAPHRAGM • Common causes of unilateral hemidiaphragm elevation include: 1 1. Lung volume loss (atelectasis, lobar collapse, partial lung resection, radiation fibrosis, congenital hypoplasia) 2. Eventration 3. Abdominal disease (dilated stomach or colon, hepatomegaly, splenomegaly, subphrenic abscess) 4. Phrenic nerve paralysis 5. Splinting 6. Mimics (subpulmonic pleural effusion, large pleural mass, diaphragmatic hernia) • Diaphragmatic paralysis is most frequently caused by interruption of the phrenic nerve, and may be unilateral or bilateral. Phrenic nerve invasion by a malignant neoplasm and trauma related to cardiothoracic surgery (stretch, crush, or transection) are the most common causes, although many cases are idiopathic. 1

FLUOROSCOPY • Simplest, quickest, and most practical method of assessing diaphragm movement. 1 • Primarily a qualitative method, quantitative information being indirectly obtained and limited geometrically by the divergent beam and object to film distance. 2 • Reduced, absent or paradoxical movement of the hemidiaphragm, especially during sniffing infers hemidiaphragmatic paresis or paralysis. 1-3 • Limitations: diaphragm motion may be diminished due to inflammatory processes such as pneumonia, pleuritis, pleural effusion, peritonitis, and subphrenic abscess,

265 so fluoroscopic assessment is best delayed until reversible conditions that may affect the diaphragm have been treated to resolution. 1

ULTRASOUND • Useful in the evaluation of patients with suspected abnormalities of diaphragmatic movement. 3-5 • Equivalent to in diagnosing diaphragm dysfunction. 3 • Superior to plain radiographs in the assessment of some of supradiaphragmatic causes (eg pleural effusion, pleural masses) and most subdiaphragmatic causes (hepatomegaly, subphrenic collections, etc) of elevated hemidiaphragm. 2 • Advantages: direct quantitative, quick and portable method of assessing hemidiaphragmatic movement.

COMPUTED TOMOGRAPHY • Useful for excluding mediastinal lesions causing phrenic nerve palsy and to evaluate a possible subdiaphragmatic cause for elevation of a hemidiaphragm. 6

REFERENCES 1. Gierada DS, Slone RM, Fleishman MJ. Imaging evaluation of the diaphragm. Chest Surgery Clinics of North America 1998; 8: 237-280. 2. Tarver RD, Conces DJ Jr, Cory DA, et al. Imaging of the diaphragm and its disorders. J Thorac Imag 1989; 4: 1-18. 3. Houston JG, Fleet M, Cowan MD, et al. Comparison of ultrasound with fluoroscopy in the assessment of suspected hemidiaphragmatic movement abnormality. Clinical Radiology 1995; 50: 95-98. (Prospective study 30 patients – Level III evidence) 4. Gottesman E, McCool D. Ultrasound evaluation of the paralysed diaphragm. Am J Respir Crit Care Med 1997; 155: 1570-1574. (Cohort of 30 patients – Level III evidence) 5. Cohen E, Mier A, Heywood P, et al. Excursion-volume relation of the right hemidiaphragm measured by ultrasonography and respiratory airflow measurements. Thorax 1994; 49: 885-889. (Prospective study 10 healthy subjects – Level III evidence) 6. Brink JA, Heiken JP, Semenkovich J, et al. Abnormalities of the diaphragm and adjacent structures: findings on multiplanar spiral CT scans. AJR 1994; 163: 307- 310. (Pictorial essay)

266 SOLITARY PULMONARY NODULE (NOT COMPLETELY CALCIFIED)

SOLITARY PULMONARY NODULE • Commonest causes of solitary pulmonary nodule in Australia include: 1. Primary malignancy 2. Metastases 3. Granuloma

267 4. Benign tumours such as hamartoma, adenoma, etc. 5. Rounded pneumonia 6. Hydatid disease • Completely calcified nodules are almost always benign.

PLAIN CHEST RADIOGRAPHY (CXR) • Primary initial imaging modality for solitary pulmonary nodule. 1, 2 • Provides useful information regarding nodule size, growth rate, margin characteristics, and calcifications. 1, 2 • When an abnormality is detected, an important next step is comparison with old radiographs. • If no change in lesion over 2 years, then no further imaging evaluation is indicated. 3 • If no old radiographs are available, or if the abnormality is new, CT is indicated to further characterise the lesion. 1, 2

COMPUTED TOMOGRAPHY (THIN SECTION THROUGH LESION + HELICAL WITH INTRAVENOUS CONTRAST) • Superior to plain radiographs for: • Evaluation and characterisation of solitary pulmonary nodule as benign or indeterminate. 4 • Detection of calcification and multiple lesions. 4-7 • Useful for: • Characterising the nodule and estimating the likelihood of malignancy. • Guiding transthoracic needle aspiration biopsies. • Probability that the nodule is malignant can be calculated by Bayesian means from clinical and radiological findings, thereby providing assistance in the choice of definitive investigative/therapeutic strategies. 8 • Standard strategies include immediate , non-thoracotomy biopsy of the nodule (usually by transthoracic needle aspiration), and “watch and wait” with serial chest radiographs. 8 • Recognition of benign calcification patterns (concentric, uniform, popcorn, central) carry an extremely low likelihood of malignancy and thus can obviate further evaluation. 2 • Growth of the nodule during the watch and wait period is an indication for prompt thoractomy. 8 • The most cost-effective strategy for evaluation of solitary pulmonary nodule was found to be dependent upon the pretest probability of malignancy. 9 1. When the pretest probability was less than 0.12, a wait-and watch strategy proved to have the best incremental cost-effectiveness ratio (ICER). 2. The CT-plus-PET strategy had the most favourable ICER when the pretest probability for having a malignant nodule was 0.12 to 0.69. 3. When the pretest probability of malignancy was between 0.69 and 0.90, a CT strategy followed by either biopsy or surgery was best. 4. When the pretest probability was greater than 0.90, a surgical strategy was best. • If a lesion is indeterminate on CT, quantitation of degree of enhancement with contrast enhanced CT may be helpful in distinguishing a benign from malignant lesion. 10, 11

268 TRANSTHORACIC FINE NEEDLE ASPIRATION / BIOPSY (TTNB) • >90% sensitivity for malignant lesions. 12-14 • Superior diagnostic yield compared to bronchoscopic biopsy. 15 • May help to avoid thoractomy if a benign diagnosis is obtained. • Particularly useful in patients who refuse surgery or for those with a very high surgical risk. • Method of FNA/Biopsy should be discussed with radiologist. TTNB can be done under CT or fluoroscopic guidance. US can be used to guide biopsy of peripheral lesions. 16 • CT allows better planning of the needle path and safe biopsy of lesions located in proximity to vascular structures or nerves. Fluoroscopy allows real-time monitoring of the needle course and is often easier in patients who are less cooperative with breath holding, since the needle can be directed into the lesion even if the patient is breathing. Fluoroscopic biopsies are often faster, since no delays are introduced while waiting for images to be reconstructed and displayed. 17 • Limitations: • Significant risk of false negative results. 12-14 • Invasive procedure with potential risks and complications.

POSITRON EMISSION TOMOGRAPHY (PET) • High sensitivity (89-100%) and specificity (79-100%) for detecting malignancy in the solitary pulmonary nodule. 18-21 • Current medicare rebatable indication for PET in the evaluation of solitary pulmonary nodule is a non-diagnostic fine needle aspiration biopsy. • Advantages: • Superior to traditional Bayesian approach for correctly classifying lesions as benign or malignant. 19 • CT plus PET strategy has been found to be most cost effective when the pretest probability of having a malignant nodule was 0.12 to 0.69. 9 • Provides simultaneous diagnostic and staging information by detecting occult metastases and prevents unnecessary surgery. 22 • Limitations: 22 • Inability to depict certain types of lesions including bronchoalveolar carcinoma and carcinoid cancers. • False positives can occur in solitary pulmonary nodules with inflammatory components such as anthrosilicotic nodules and some infectious nodules. • Disadvantages: limited availability and high cost.

269 REFERENCES 1. Ost D, Fein A. Evaluation and management of the solitary pulmonary nodule. Am J Respir Crit Care Med 2000; 162: 782-787. 2. Webb WR. Radiologic evaluation of the solitary pulmonary nodule. AJR 1990; 154: 701-708. (Review) 3. Yenkelevitz D, Henschke CI. Does 2-year stability imply pulmonary nodules as benign? AJR 1997; 168: 325-328. 4. Siegelman SS, Khouri NF, Leo FP, et al. Solitary pulmonary nodules: CT assessment. Radiology 1986; 160: 307-312. (Prospective study 643 lesions – Level II/III evidence) 5. Zerhouni EA, Stitik FP, Siegelman SS, et al. CT of the pulmonary nodule: a cooperative study. Radiology 1986; 160: 319-327. (Prospective study 384 nodules with no calcification on plain radiographs – Level II/III evidence) 6. Berger WG, Erly WK, Krupinski EA, et al. The solitary pulmonary nodule on chest radiography: can we really tell if the nodule is calcified? AJR 2001; 176: 201-204. (Retrospective study 35 SPN – Level III evidence) 7. Costello P, Anderson W, Blume D. Pulmonary nodule: evaluation with spiral volumetric CT. Radiology 1991; 179: 875-876. (Prospective study 20 patients – Level III evidence) 8. Gould MK, Lillington GA. Strategy and cost in investigating solitary pulmonary nodules. Thorax 1998; 53(S2): S32-S37. 9. Gambhir SS, Shepherd JE, Shah BD, et al. Analytical decision model for the cost- effective management of solitary pulmonary nodules. J Clin Oncol 1998; 16: 2113- 2125. (Level II evidence) 10. Swensen SJ, Viggiano RW, Midthun DE, et al. Lung nodule enhancement at CT: multicenter study. Radiology 2000; 214: 73-80. (Large Prospective multicenter study – Level II/III evidence) 11. Yamashita K, Matsunobe S, Tsuda T, et al. Solitary pulmonary nodule: preliminary study of evaluation with incremental dynamic CT. Radiology 1995; 194: 399-405. (Retrospective study 32 patients with SPN– Level III evidence) 12. Lucidarme O, Howarth N, Finet J-F, et al. Intrapulmonary lesions: percutaneous automated biopsy with detectable, 18-gauge, coaxial cutting needle. Radiology 1998; 207: 759-765. (Retrospective study cohort of 89 consecutive patients who had TNB – Level III evidence) 13. Khouri NF, Stitik FP, Erozan YS, et al. Transthoracic needle aspiration biopsy of benign and malignant lung lesions. AJR 1985; 144: 281-288. (Cohort of 650 consecutive patients – Level II evidence) 14. Lee SI, Shephard JL, Boiselle PM, et al. Role of transthoracic needle biopsy in patient treatment decisions. Radiology 1996; 201(P): 269. 15. Yankelevitz DF, Heneschke C, Koizumi J, et al. CT-guided transthoracic needle biopsy following indeterminate fibreoptic bronchoscopy in solitary pulmonary nodules. Clinical Imaging 1998; 22: 7-10. (Cohort of 48 patients – Level III evidence) 16. Sheth S, Hamper UM, Stanley DB, et al. US guidance for thoracic biopsy: a valuable alternative to CT. Radiology 1999; 210: 721-726. (Prospective study 34 lesions – Level III evidence) 17. Shaffer K. Role of radiology for imaging and biopsy of solitary pulmonary nodules. Chest 1999; 116: 519S-522S. 18. Weber W, Young C, Abdel-Dayem HM, et al. Assessment of pulmonary lesions with 18F-Fluorodeoxyglucose positron emission imaging using coincidence mode gamma camera. J Nucl Med 1999; 40: 574-578. (Prospective multicenter study 96 patients with 24 controls – Level II evidence)

270 19. Dewan NS, Shehan CJ, Reeb SD, et al. Likelihood of malignancy in a solitary pulmonary nodule: comparison of Bayesian analysis and results of FDG- PET scan. Chest 1997; 12: 416-422. (Retrospective study cohort of 52 consecutive patients – Level II/III evidence) 20. Lowe VJ, Fletcher JW, Gobar L, et al. Prospective investigation of positron emission tomography in lung nodules. J Clin Oncol 1998; 16(3): 1075-1084. (Prospective multicenter trial 105 patients – Level II evidence) 21. Prauer HW, Weber JW, Romer W, et al. Controlled prospective study of positron emission tomography using the glucose analogue 18F-fluorodeoxyglucose in the evalution of pulmonary nodules. Br J Surg 1998; 85: 1506-1511. (Prospective study 50 patients – Level II/III evidence) 22. Coleman RE. PET in lung cancer. J Nucl Med 1999; 40(5): 814-820.

Further Reading 1. Leef JL III, Klein JS. The solitary pulmonary nodule. Radiologic Clinics of North America 2002; 40(1):123-143. 2. Shaham D, Guralnik L. The solitary pulmonary nodule: radiologic considerations. Seminars in US, CT, and MRI 2000; 21(2): 97-115. 3. Vazquez MF, Yankelevitz DF. The radiologic appearance of solitary pulmonary nodules and their cytologic-histologic correlation. Seminars in US, CT, and MRI 2000; 21(2): 149-162. 4. Yankelevitz DF, Wisnivesky JP, Henschke CI, et al. Comparison of biopsy techniques in assessment of solitary pulmonary nodules. Seminars in US, CT, and MRI 2000; 21(2): 139-148. 5. Goldsmith SJ, Kostakoglu L. Role of nuclear medicine in the evaluation of the solitary pulmonary nodule. Seminars in US, CT, and MRI 2000; 21(2): 129-138.

271 STAGING OF NON SMALL CELL LUNG CANCER

STAGING OF NON-SMALL CELL LUNG CANCER (NSCLC) • Accurate staging is essential for therapeutic decision making and prognostic information. 1 • TNM classification system of staging. 1, 2 • Important to accurately differentiate stages I to IIIA (potentially resectable) from stage IIIB to IV (nonresectable) cancer. 2

PLAIN CHEST RADIOGRAPHY (CXR) • Routinely indicated in patients with lung cancer. 2 • Limitations: lacks sensitivity in the detection of mediastinal lymph node metastases, and in chest wall and mediastinal invasion. 3

COMPUTED TOMOGRAPHY (CT) • Initial investigation of choice in staging of non-small cell lung cancer. 2 • Allows evaluation of the size and extent of the primary tumour, and metastatic spread to mediastinum and upper abdomen. 2 • Upper abdominal Imaging is routinely indicated (especially as part of thoracic CT staging) to detect metastatic disease in adrenal glands and liver. 2 • Limitations: • Moderate accuracy for mediastinal lymph node involvement (~60% sensitivity and specificity of 60-90%). 3-6 • Limited accuracy in confirming chest wall or local mediastinal invasion. 3 • Limited evaluation of superior sulcus tumours due to its axial format and streak artefacts from the shoulders.

272 • Difficult to distinguish between benign and malignant enlargement of adrenals. Therefore, biopsy is indicated to differentiate an adenoma from metastatic disease. 7

CT HEAD • Routine use of CT head in asymptomatic patients with NSCLC is not indicated. 8 • Some centres advocate routine CT head for early detection of brain metastases in patients with potentially operable lung cancer. 9, 10

MAGNETIC RESONANCE IMAGING (MRI) • Comparable accuracy to that of CT in T classification and detection of mediastinal nodal metastasis. 3 • Superior to CT in detection of direct mediastinal invasion, in the evaluation of chest wall invasion and the local staging of superior sulcus tumours. 3, 11, 12

BONE SCAN • Routine skeletal imaging is usually not indicated. 13 • Indicated if there is equivocal bone lesion on PET scan.

POSITRON EMISSION TOMOGRAPHY (PET) • Superior to other modalities in differentiating resectable from nonresectable disease. 7 • Indicated in all patients with non-small cell lung cancer unless CT scan unequivocally shows evidence of stage ≥3b disease. • Advantages: • Superior to CT for nodal staging of non-small cell lung cancer. 4, 6, 14-17 • Superior to CT and bone scan for detection of distant metastases. 4 • More cost-effective than CT. 4, 18, 19 • Disadvantages: 4 • Relatively poor resolution to assess tumour size and determine invasion into adjacent tissues, such as chest wall, large vessels, or other features that define tumour status. • Low sensitivity for detection of brain metastases. • Limited availability and high expense.

273 REFERENCES 1. Patz EF Jr. Imaging bronchogenic carcinoma. Chest 2000; 117: 90S-95S. 2. Park BJ, Louie O, Altorki N, et al. Staging and the surgical management of lung cancer. Radiologic clinics of North America 2000; 38(3): 545-561. 3. Webb WR, Gatsonis C, Zerhouni EA, et al. CT and MR imaging in staging non- small cell bronchogenic carcinoma: report of the Radiologic Diagnostic Oncology Group. Radiology 1991; 178(3): 705-713. (Prospective study 170 patients – Level II/III evidence) 4. Marom E, McAdams HP, Erasmus JJ, et al. Staging non-small cell lung cancer with whole-body PET. Radiology 1999; 212: 803-809. (Prospective study 139 consecutive patients – Level II evidence) 5. McLoud TC, Bourgouin PM, Greenberg RW, et al. Bronchogenic carcinoma: analysis of staging in the mediastinum with CT by correlative lymph node mapping and sampling. Radiology 1992; 182(2): 319-323. (Prospective study 143 consecutive patients – Level II evidence) 6. Gdeedo A, van Schil P, Courthouts B, et al. Prospective evaluation of computed tomography and in mediastinal lymph node staging. Eur Resp J 1997; 10: 1547-1551. (Level II/III evidence) 7. Oliver TW, Bernardino ME, Miller JI, et al. Isolated adrenal masses in non small- cell bronchogenic carcinoma. Radiology 1984; 153: 217-218. (Prospective study 330 patients – Level II/III evidence) 8. Colice GL, Birkmeyer JD, Black WC, et al. Cost-effectiveness of head CT in patients with lung cancer without clinical evidence of metastases. Chest 1995; 108: 1264-1271. (Decision analysis hypothetical cohort – Level III evidence) 9. Yokoi K, Kamiya N, Matsuguma H, et al. Detection of brain metastasis in potentially operable non-small cell lung cancer: a comparison of CT and MRI. Chest 1999; 115: 714-719. (Prospective study sequential comparison 332 patients – Level III evidence) 10. Salbeck R, Grau HC, Artmann H. Cerebral tumour staging in patients with bronchial carcinoma by computed tomography. Cancer 1990; 66(9): 2007-2011. (Retrospective study 271 patients – Level III evidence) 11. Heelan RT, Demas BE, Caravelli JF, et al. Superior sulcus tumors: CT and MR imaging. Radiology 1989; 170(3): 637-641. (Prospective study 31 patients – Level III evidence ) 12. Padovani B, Mouroux J, Seksik L, et al. Chest wall invasion by bronchogenic carcinoma: evaluation with MR imaging. Radiology 1993; 187: 33-38. (Prospective study 34 patients – Level II/III evidence) 13. Michel F, Soler M, Imhof E, et al. Initial staging of non-small cell lung cancer: value of routine radioisotope bone scanning. Thorax 1991; 46(7): 469-473. (Prospective study 110 consecutive patients – Level II evidence) 14. Dwamena BA, Sonnad SS, Angobaldo JO, et al. Metastases from non-small cell lung cancer: mediastinal staging in the 1990s – Meta-analytic comparison of PET and CT. Radiology 1999; 213: 530-536. (Meta-analysis – Level II/III evidence) 15. Gupta NC, Graeber GM, Rogers JS II, et al. Comparative efficacy of positron emission tomography with FDG and computed tomographic scanning in preoperative staging of non-small cell lung cancer. Ann Surg 1999; 229: 286-291. (Prospective study 103 patients – Level II/III evidence) 16. Vansteenkiste JF, Mortelmans KA. FDG-PET in the locoregional staging of non- small cell lung cancer: a comprehensive review of the Leuven Lung Cancer Group experience. Clin Pos Imaging 1999; 2: 223-231. 17. Steinert HC, Hauser M, Allemann F, et al. Non-small cell lung cancer: nodal staging with FDG PET versus CT with correlative lymph node mapping and sampling.

274 Radiology 1997; 202: 441-446. (Prospective study cohort of 47 patients – Level III evidence) 18. Gambhir SS, Hoh CK, Phelps ME, et al. Decision tree sensitivity analysis for cost- effectiveness of FDG-PET in the staging and management of non small-cell lung carcinoma. J Nucl Med 1996; 37: 1428-1436. 19. Shepherd JE, Phelps ME, Czernin J, et al. Cost-effectiveness analysis for the role of FDG-PET in lung carcinoma. J Nucl Med 1999; 40: 56P.

Further Reading 1. Goldsmith SJ, Kostakoglu L. Nuclear medicine imaging of lung cancer. Radiologic Clinics of North America 2000; 38(2): 511-524.

275 SUSPECTED MEDIASTINAL MASS

PLAIN CHEST RADIOGRAPHS (CXR) • An erect posteroanterior and lateral chest radiographs, taken after a good inspiratory effort, are required to assess the presence and location of a mediastinal mass. 1 • Comparison with old chest films is important to help establish if the abnormality is new. 1

COMPUTED TOMOGRAPHY (CT) • Imaging modality of choice for evaluation of a suspected mediastinal mass. 1, 2 • Provides useful information in regards to: 1, 3 1. Location of the mass (anterior, posterior, middle mediastinum) 2. CT characteristics of the mass (fat, fluid, solid) 3. Likely origin (neural, oesophagus, airways, nodes etc) 4. Mode of extension or spread • Measurement of CT density increases the specificity of differential diagnosis of mediastinal masses. 1, 3 1. Lesions that may contain fluid-density areas include goiters, thymic cysts, thymomas, teratomas, lymphomas, necrotic nodes from inflammatory or malignant causes, pericardial cysts, bronchogenic and oesophageal duplication cysts. Low-density appearance may also be produced by lesions that contain fat, such as thymolipomas and teratomas. 2. Lesions containing calcifications include goiters, thymomas, lymphomas (usually treated), carcinoid tumours, inflammatory masses (tuberculosis, histoplasmosis, rarely sarcoid), aneurysms, occasional neurogenic tumours of the ganglion series, and oesophageal leiomyomas. • Contrast enhancement on CT scan helps narrow the radiographic differential diagnosis and provides clinically significant information on compression, encasement, or obstruction of mediastinal vessels. Lesions showing significant enhancement after contrast injection include goiters, parathyroid adenomas, Castleman’s disease, vascular lesions, paragangliomas, and some metastases. 1

276 • Further investigation/management will depend on the above CT findings. 1 • Advantages of CT (compared to MRI): 4, 5 • Spatial resolution. • Detection of calcification and bone destruction. • Screening of lung, liver and adrenal metastases in a single study. • Useful in guiding needle aspiration biopsy of masses. • Wider availability. • Disadvantages: • Exposure to ionising radiation. • Involves use of contrast agent.

MAGNETIC RESONANCE IMAGING (MRI) • Largely used as an adjunct to CT scanning in the evaluation of mediastinal abnormalities. 6 • Often provides additional information about the nature, location, and extent of disease. 7 • Useful in confirming the cystic nature of mediastinal lesions that appear solid on CT, and by revealing small amounts of intralesional fat, can suggest the diagnosis of haemangioma, teratoma, or extramedullary haematopoiesis. 6 • Preferred modality for imaging neurogenic tumours. 6 • Advantages: 6 • Multiplanar imaging. • High contrast resolution. • Does not involve use of contrast agent. • Disadvantages: limited availability and high expense.

ANGIOGRAPHY • Largely rendered unnecessary by contrast CT and MRI. 1 • Useful in the evaluation of vascular lesions (aneurysm, haemangioma, and arteriovenous malformation) and to clarify vascular invasion by tumour masses. 1 • May be used to determine the blood supply in large masses of questionable origin prior to surgery. 1 • Role in the embolisation of highly vascular lesions prior to surgery. 1

277 REFERENCES 1. Moore EH. Radiologic evaluation of mediastinal masses. Chest Surgery Clinics of North America 1992; 2(1): 1-22. 2. Wright CD, Mathisen DJ. Mediastinal tumors: diagnosis and treatment. World J Surg 2001; 25: 204-209. 3. Feigin DS, Padua EM. Mediastinal masses: a system for diagnosis based on computed tomography. CT 1986; 10: 11-21. 4. Gamsu G, Stark DD, Webb WR, et al. Magnetic resonance imaging of benign mediastinal masses. Radiology 1984; 151: 709-713. (Retrospective study 8 case controls – Level IV evidence) 5. Levitt RG, Glazer HS, Roper CL, et al. Magnetic resonance imaging of mediastinal and hilar masses: comparison with CT. AJR 1985; 145: 9-14. (Cohort of 37 patients with bronchogenic carcinoma and 11 patients with mediastinal and hilar masses – Level III evidence) 6. Erasmus JJ, McAdams HP, Donnelly LF, et al. MR imaging of mediastinal masses. MRI Clin North America 2000; 8(1): 59-89. 7. Von Schulthess GK, McMurdo K, Tscholakoff D, et al. Mediastinal masses: MR imaging. Radiology 1986; 158: 289-296. (Retrospective study cohort of 75 patients – Level III evidence)

Further Reading 1. Kim Y, Lee KS, Yoo JH, et al. Middle mediastinal lesions: imaging findings and pathologic correlation. Eur J Radiol 2000; 35: 30-38.

278 SUSPECTED PULMONARY EMBOLUS (PE)

279 PULMONARY EMBOLUS • Accurate and prompt diagnosis of acute PE requires an interdisciplinary team approach and may be difficult because of non-specific clinical, laboratory, and radiographic findings. 1

CLINICALLY “MAJOR” PULMONARY EMBOLUS (PE) • If massive PE is clinically obvious, start heparin immediately or consider other treatments such as thrombolysis (or surgical embolectomy). 1 • Spiral CT and/ or echocardiography can be performed if indicated after initial therapy.

PLAIN CHEST RADIOGRAPHS (CXR) • Mainly used to exclude other diagnoses that clinically mimic PE and to aid in the interpretation of the V/Q scan. 2, 3 • May help in deciding the optimum sequence of investigation: 2, 4 1. A normal pre-test CXR is more often associated with a definitive (normal or high probability) V/Q scan and hence these patients may be investigated with V/Q scan. 2. An abnormal CXR increases the prevalence of non-diagnostic V/Q scans and hence in these patients spiral CT may be used as a first-line investigation. • CXR is abnormal in most cases of PE but the findings are non-specific. 3, 5 • Common radiographic findings include atelectasis, pleural effusion, parenchymal opacification, and elevation of a hemidiaphragm. 3, 5 • Classic radiographic findings of pulmonary infarction, such as a wedge-shaped pleural based triangular opacity with apex pointing toward the hilus (Hampton’s hump) or decreased vascularity (Westermark’s sign), are suggestive of PE but are infrequent. 3

VENTILATION-PERFUSION (V/Q) SCAN • Initial screening test for suspected PE. 1 • 99% accuracy of a normal or near-normal V/Q scan. 6, 7 • 98% specificity of high-probability reading. 6, 7 • Based on the available evidence, the following conclusions can be made: 1 1. A normal V/Q scan interpretation excludes the diagnosis of clinically significant PE. 2. Clinically stable patients with a high probability V/Q scan interpretation and a high clinical likelihood of PE require treatment and need no further diagnostic tests to confirm the diagnosis. 3. Patients with a low probability V/Q scan interpretation and a low clinical likelihood of PE do not require angiography or anticoagulation. 4. Further investigations are indicated in cases with intermediate probability V/Q scan or when there is discordant clinical probability. • Advantages: low radiation burden compared to spiral CT. • Limitations: high rate of non-diagnostic readings and low specificity in patients with comorbid cardiopulmonary diseases. 6

SPIRAL COMPUTED TOMOGRAPHY (CT) • Highly sensitive and specific for diagnosing central PE. 8-10 • Comparable specificity to that of high-probability V/Q scan. 8 • Useful for the diagnosis of pulmonary in patients with nondiagnostic V/Q scans. 11, 12

280 • Several different imaging pathways are possible since the advent of fast helical CT scanning. Spiral CT is becoming the favoured investigation over pulmonary angiography in many centres and is increasingly being used as the initial imaging study, especially in patients with abnormal chest radiographs in whom V/Q scan is more likely to be nondiagnostic, in the diagnosis of PE. 13-15 This strategy is still under assessment. 8 • More recently published studies support the use of spiral CT in combined strategies that include V/Q scans and leg ultrasonography. 12, 16 • The safety of withholding anticoagulant treatment in patients with negative results on spiral CT is uncertain, therefore these patients may need further investigation. 8-10 However, more recently emerging data supports the use of spiral CT to help exclude clinically significant PE. 13, 17-19 • Advantages: • Fast, non-invasive test. • Potential to image the pulmonary vasculature extending from the right and left main pulmonary arteries to at least the segmental and possibly the subsegmental arteries. • Can demonstrate pathology other than PE. 13 • Has fewer indeterminate results compared to V/Q scan. 20 • Disadvantages: • Insensitive for diagnosing subsegmental clots. 9, 10 • Expensive, use of iodinated contrast material, and radiation exposure

LEG DOPPLER ULTRASOUND • Stable patients with suspected acute PE, non-diagnostic V/Q scan, and adequate cardiopulmonary reserve may undergo non-invasive evaluation of lower extremities with doppler US to establish the need for anticoagulation. 21, 22 • Diagnostic strategies, incorporating Leg Doppler US, for suspected PE have been found to be both useful and cost-effective. 21-23 • If positive for deep vein thrombosis, then it is an indication to assume the diagnosis of thromboembolism and to commence anticoagulation. • PE can be safely excluded in patients with a low clinical probability of PE, a nondiagnostic lung scan and a normal leg Doppler US. 24 • Pulmonary angiogram should be considered in patients with high clinical probability of PE but a low probability V/Q scan and a negative leg Doppler US. 25 • Leg Doppler US can also be used to evaluate suspected PE in patients who have non- diagnostic spiral CT to avoid doing pulmonary angiography. • Advantages: non-invasive. • Limitations: non- specific. • Venography is an alternative to Doppler US.

PULMONARY ANGIOGRAM • Gold standard for detection of PE. 6, 26 • Indicated when there is high clinical suspicion of PE but normal or inconclusive non-invasive tests (V/Q scan, Spiral CT and leg Doppler US). • The yield of pulmonary angiography reduces after 30-36 hours following PE, but a negative angiogram in these circumstances rarely is associated with a subsequent significant PE. 26 • V/Q scan serves as an accurate guide for determining the initial approach for pulmonary angiography. 27

281 • Advantages: provides superior detail of subsegmental vessels compared to spiral CT. • Disadvantages: invasive, expensive, involves the use of contrast material, 0.3% mortality rate and 1-3% rate of major complications. 28

INFERIOR VENA CAVA FILTERS • Routine use of IVC filters is not recommended. • Should be considered (preceded by pulmonary angiography) in patients with: 29 • Recurrent pulmonary emboli arising from lower limb or pelvis despite therapeutic anticoagulation. • Contraindication to anticoagulation.

ECHOCARDIOGRAPHY • Used primarily in the evaluation of haemodynamically significant PE. 30, 31 • Transthoracic echocardiography (TTE) detects right heart strain and pulmonary hypertension (findings which become evident only with large or multiple PE). 30, 31 • Transesophageal echocardiography (TEE) provides more consistent cardiac imaging than TTE and permits direct visualisation of emboli in the right main up to the point of the interlobar trunks and lobar arteries. 31 • Advantages of TTE: noninvasive, can be performed at the bedside and can exclude other causes of haemodynamic instability (such as left-ventricular dysfunction, tamponade, and valvular insufficiency). 30, 31

282 REFERENCES 1. Worsley DF, Alavi A. Radionuclide imaging of acute . Radiologic Clinics of North America 2001; 39(5): 1035-1052. (Review) 2. Garg K. CT of pulmonary thromboembolic disease. Radiologic Clinics of North America 2002; 40(1): 111-122. (Review) 3. Worsley DF, Alavi A, Aronchick JM, et al. Chest radiographic findings in patients with acute pulmonary embolism: observations from the PIOPED study. Radiology 1993; 189: 133-136. (Level II evidence) 4. Forbes KPN, Reid JH, Murchison JT. Do preliminary chest X-ray findings define the optimum role of pulmonary scintigraphy in suspected pulmonary embolism? Clinical Radiology 2001; 56: 397-400. (Retrospective cohort of 613 consecutive patients – Level II evidence) 5. Elliott CG, Goldhaber SZ, Visani L, et al. Chest radiographs in acute pulmonary embolism: results from the International Cooperative Pulmonary Embolism Registry. Chest 2000; 118: 33-38. (Prospective observational study 2454 consecutive patients – Level II/III evidence) 6. The PIOPED investigators. Value of the ventilation/perfusion scan in acute pulmonary embolism: results of the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED). JAMA 1990; 263: 2753-2759. (Prospective study random sample of 933 patients - Level I/II evidence) 7. Worsley DF, Alavi A. Comprehensive analysis of the results of the PIOPED study. J Nucl Med 1995; 36: 2380-2387. (Level I/II evidence) 8. Kline JA, Johns KL, Colucciello SA, et al. New diagnostic tests for pulmonary embolism. Ann Emeg Med 2000; 35: 168-180. (Systematic review – Level I/II evidence) 9. Rathbun SW, Raskob GE, Whitsett TL. Sensitivity and specificity of helical computed tomography in the diagnosis of pulmonary embolism: a systematic review. Ann Intern Med 2000; 132: 227-232. (Systematic review – Level I/II evidence) 10. Mullins MD, Becker DM, Hagspiel KD, et al. The role of spiral volumetric computed tomography in the diagnosis of pulmonary embolism. Arch Intern Med 2000; 160: 293-298. (Systematic review- Level I/II evidence) 11. Chen S-W, Mouratidis B. Comparison of lung scintigraphy and CT angiography in the diagnosis of pulmonary embolism. Australasian Radiology 2002; 46: 47-51. (Prospective cohort of 116 consecutive patients – Level II evidence) 12. Wilson HTH, Meagher TMM, Williams SJ. Combined helical computed tomographic pulmonary angiography and lung perfusion scintigraphy for investigating acute pulmonary embolism. Clinical Radiology 2002; 57: 33-36. (Prospective observational study of 808 consecutive patients – Level II evidence) 13. Garg K, Sieler H, Welsch CH, et al. Clinical validity of helical CT being interpreted as negative for pulmonary embolism: implications for patient management. AJR 1999; 172: 1627-1631. (Retrospective study 78 consecutive patients with V/Q scan controls – Level III evidence) 14. Goodman LR, Lipchik RJ. Diagnosis of acute pulmonary embolism: time for a new approach. Radiology 1996; 199: 25-27. 15. Cross JJL, Kemp PM, Walsh CG, et al. A randomized trial of spiral CT and ventilation perfusion scintigraphy for the diagnosis of pulmonary embolism. Clinical Radiology 1998; 53: 177-182. (Prospective randomised trial 78 patients – Level II evidence) 16. Perrier A, Howarth N, Didier D, et al. Performance of helical computed tomography in unselected outpatients with suspected pulmonary embolism. Ann Intern Med

283 2001; 135: 88-97. (Prospective observational study 299 patients – Level II/III evidence) 17. Goodman LR, Lipchik RJ, Kuzo RS, et al. Subsequent pulmonary embolism: risk after a negative helical CT pulmonary angiogram – Prospective comparison with scintigraphy. Radiology 2000; 215: 535-542. (Prospective study 588 patients – Level II/III evidence) 18. Ost D, Rozenshtein A, Saffran L, et al. The negative predictive value of spiral computed tomography for the diagnosis of pulmonary embolism in patients with nondiagnostic ventilation-perfusion scans. Am J Med 2001; 110: 16-21. (Prospective observational study 103 consecutive patients – Level II/III evidence) 19. Swensen SJ, Sheedy PF, Ryu JH, et al. Outcomes after withholding anticoagulation from patients with suspected acute pulmonary embolism and negative computed tomographic findings: a cohort study. Mayo Clin Proc 2002; 77: 130-138. (Retrospective cohort study 1512 consecutive patients – Level II evidence) 20. Crawford T, Yoon C, Wolfson K, et al. The effect of imaging modality on patient management in the evaluation of pulmonary thromboembolism. J Thoracic Imaging 2001; 16: 163-169. (Retrospective study 138 consecutive V/Q scans compared to 149 consecutive CTA – Level II/III evidence) 21. Beechman RP, Dorfman GS, Cronan JJ, et al. Is bilateral lower extremity compression sonography useful and cost-effective in the evaluation of suspected pulmonary embolism? AJR 1993; 161: 1289-1292. (Cohort of 223 consecutive patients - Level II/III evidence) 22. Stein PD, Hull RD, Pineo G, et al. Strategy that includes serial noninvasive leg tests for diagnosis of thromboembolic disease in patients with suspected acute pulmonary embolism based on data from PIOPED. Arch Intern Med 1995; 155: 2101-2104. (Level II/III evidence) 23. Perrier A, Buswell L, Bounameaux H, et al. Cost-effectiveness of noninvasive diagnostic aids in suspected pulmonary embolism. Arch Intern Med 1997; 157: 2309-2316. (Decision analysis – Level III evidence) 24. Perrier A, Miron M-J, Desmarais S, et al. Using clinical evaluation and lung scan to rule out suspected pulmonary embolism: is it a valid option in patients with normal results of lower limb venous compression ultrasonography? Arch Intern Med 2000; 160: 512-516. (Two consecutive cohorts pooled together with total of 1034 consecutive patients – Level II evidence) 25. Meyerovitz MF, Mannting F, Polak JF, et al. Frequency of pulmonary embolism in patients with low-probability lung scan and negative lower extremity venous ultrasound. Chest 1999; 115: 980-982. (Retrospective study cohort of 62 patients – Level II/III evidence) 26. Van Beek EJR, Brouwers EMJ, Song B, et al. Clinical validity of a normal pulmonary angiogram in patients with suspected pulmonary embolism – a critical review. Clinical Radiology 2001; 56: 838-842. (Critical analysis of 8 studies – Level II evidence) 27. Davey NC, Smith TP, Hanson MW, et al. Ventilation-perfusion lung scintigraphy as a guide for pulmonary angiography in the localization of pulmonary emboli. Radiology 1999; 213: 51-57. 28. Stein PD, Athanasoulis C, Alavi A, et al. Complications and validity of pulmonary angiography in acute pulmonary embolism. Circulation 1992; 85: 462-468. 29. ACCP consensus committee on pulmonary embolism. Opinions regarding the diagnosis and mangement of venous thromboembolic disease. Chest 1998; 113: 499-504. (Level II evidence)

284 30. Rudoni RR, Jackson RE, Godfrey GW, et al. Use of two-dimensional echocardiography for the diagnosis of pulmonary embolus. J Emerg Med 1998; 16: 5-8. (Retrospective case control study 71 patients – Level IV evidence) 31. Vieillard-Baron A, Qanadli SD, Antakly Y, et al. Transesophageal echocardiography for the diagnosis of pulmonary embolism with acute cor pulmonale: a comparison with radiologic procedures. Intensive Care Med 1998; 24: 429-433. (Prospective study 44 consecutive patients – Level II/III evidence)

Further Reading 1. Padley SPG. Lung scintigraphy vs spiral CT in the assessment of pulmonary emboli. Br J Radiol 2002; 75: 5-8. (Commentary) 2. Safriel Y, Zinn H. CT pulmonary angiography in the detection of pulmonary emboli: a meta-analysis of sensitivities and specificities. J Clin Imaging 2002; 26: 101-105. (Meta- analysis of 12 studies – Level II evidence) 3. Goodman LR. Venous thromboembolic disease: CT evaluation. Q J Nucl Med 2001; 45: 302-310. 4. Donkers-van Rossum AB. Diagnostic strategies for suspected pulmonary embolism. Eur Respir J 2001; 18: 589-597.

285

Chapter 3

Medium of Distribution

286 MEDIUM OF DISTRIBUTION

METHOD OF DEVELOPMENT OF ELECTRONIC ENVIRONMENT Information and Technology advisor (Mr Fred Valton) was appointed to help design and develop user-friendly electronic format for presentation and dissemination of Diagnostic Imaging Pathways (DIP).

HTML and JavaScript were used to both mark-up the clinical and academic content as well as render the navigational elements. This resulted in an Internet browser-friendly vehicle for the presentation of the pathways, which in turn offered the following advantages; a relatively simple process for the maintenance and update of content, operating platform independence for dissemination to improve their reach in the community, the opportunity for media and network-based delivery.

An iterative approach was adopted in the design process. Early drafts and ideas were submitted to the developers of clinical and academic content for suggestion and comment. The environment was then presented to potential users and their representatives for review. Functional enhancements, and changes to the interface followed this review. Clinical and academic content was introduced progressively after it was approved for release. Testing was carried out to ensure the product was free of content and technical errors.

RESULTS DIP is distributed in two ways; via the hospital Intranet and available to any computer that is logged onto the network, as well as on compact disc. Intranet delivery has the advantage of being fast since the hospital offers mostly 100Mb links to desktop computers and also allows for delivery from a master source, with the advantage that changes in the content of DIP are made available instantaneously across the network. Intranet delivery has the disadvantage that computers need to be connected to the hospital Intranet to gain access to DIP. Distribution on compact disk was designed to address this shortcoming, making the DIP available to General Practitioners and any other clinician unable to log onto the network. Features of the electronic environment include: • Intuitive navigation. • 'Pop-up' summaries. 287 • Internal hyperlinks to references. • A search facility. • Printer friendly versions in both Microsoft Word and Adobe Acrobat compatible formats.

The Compact Disc (CD) version of the Diagnostic Imaging Pathways is attached on this page.

288

Chapter 4

Dissemination and Implementation

289 DISSEMINATION AND IMPLEMENTATION

INTRODUCTION It is recognised that simply making guidelines available to clinicians is insufficient for getting them accepted and used 30. A vigorous and multifaceted approach is required to change clinicians' behaviour 19. Ideally, the approach should include the use of opinion leaders and 'champions', endorsement by clinical groups, local adaptation, practice visits from influential experts, small group workshops, felicitous use of information technology, reminder systems and provision of incentives (or at least the removal of disincentives).

METHODOLOGY The dissemination and implementation methodology employed most of the above facets and had two phases; raising general awareness of DIP, followed by intensive marketing activities. For the latter, two groups of clinicians were targeted: hospital-based clinicians in the Departments of General Medicine, General Surgery and Emergency Medicine; general practitioners in two Divisions of General Practice.

The Project was temporarily bifurcated because of different service characteristics and different data availability in 'hospital' and 'general practice' environments. Collaboration with the Canning Division of General Practice (DGP) and the Perth & Hills DGP was secured for the general practice trial. Two half-time Project Officers were appointed for 6 months May 2003 to carry out the separate trials with the following broad purpose: • Develop a methodology for eventual large scale dissemination. • Test more rigorously the content of the pathways and the functionality of the electronic format in clinical settings. • Assess the acceptability and applicability of the pathways as a 'decision support' tool in a clinical environment. • Preliminary assessment of the impact of the pathways on requesting practice. • Further refine the pathways based on feedback from the trial.

The Project Officer for the general practice trial was based in the Canning DPG but worked across both DGPs in utilising expertise and engaging general practitioner

290 participation. The Project Officers liased throughout all phases of the work to achieve commonality where possible between the hospital and general practice trial in regard to methodology.

Earlier versions of the pathways had been accessible on the intranet of RPH via an icon with the title "Imaging Pathways" on the desktop of all staff logged onto the local area network. There were three components to the dissemination of the revised version. First, the icon was changed signalling the availability of the new product in HTML (web-browser) format on 20 May 2003. Selection of the icon resulted in the display of the home-page which included a drop-down menu of locations and topics. The pathways were also made available on compact disk (CD) in HTML format.

Second, a number of actions were taken to raise general awareness of the revised pathways: • The Director of Clinical Services was briefed on the project, and the pathways were presented and discussed at the Clinical Directors' Forum and the Grand Round in April 2003. • The project was presented at a professional development meeting of medical imaging technologists (MITs) in July 2003, because they are committed to ALARA principles (ie, reducing radiation exposures As Low As Reasonably Achieveable), and they frequently communicate with clinicians who request examinations. They are therefore in a position to encourage the use of DIP. • Posters alerting doctors and MITs to the usefulness and availability of DIP were distributed throughout common areas of the hospital in July 2003. • Brief articles about the project were published in Servio News (the hospital's newsletter) and in Imaging Services News (the Division of Imaging Services' newsletter) in September 2003.

Third, hospital departments were selected for more intensive marketing activities; viz General Medicine and General Surgery because they cover all the major indications for medical imaging included in DIP, and Emergency Medicine because it covers acute clinical situations. The following actions were taken: • Senior registrars in General Medicine and General Surgery were recruited in June 2003 to encourage junior medical officers to use DIP when imaging examinations are being considered and requested.

291 • Meetings were held with the clinical heads of the three departments in June 2003 to • Discuss the project, demonstrate DIP and obtain support for the use of DIP in their departments. • Negotiate a time to meet with staff and recruit their participation in the trial dissemination and evaluation. • Departmental meetings coinciding with the start of the 'new term' for junior medical officer rotation were attended by the Editor of DIP and the Project Officer in July 2003 to • Describe the rationale and methodology for the trial dissemination and evaluation. • Demonstrate DIP including the method of access and navigation. • Distribute the first assessment material, and collect the completed documentation. • Provide a 'show bag' to each doctor attending, which included a CD of DIP.

The methodology is summarised in Table 1.

292

TABLE 1 Dissemination and implementation methodology for hospital-based clinicians and general practitioners PHASE HOSPITAL-BASED CLINICIANS GENERAL PRACTITIONERS Raising • presentations to • 'mail-out' advertising DIP, general • hospital executive committees the trial dissemination and awareness • hospital Grand Round evaluation, and the award • professional development meetings of Continuing Professional of medical imaging technologists Development points for • posters in strategic areas of the hospital participation • articles in Newsletters Intensive • senior registrars recruited to encourage • education seminar and marketing junior medical officers to refer to DIP visits to individual GPs • Heads of Department support enlisted • demonstration of DIP • presentations to Departmental meetings and provision of CD • demonstration of DIP and method • distribution of of access via the Intranet evaluation material • distribution and collection of • notification of reward evaluation material for on-going • notification of reward for on-going participation in trial participation in trial

RESULTS With a link provided on the hospital Intranet, DIP became available to all hospital-based doctors whenever they logged onto the network from a personal computer or laptop. Selection of an icon on the 'desk-top' results in the display of the home-page which includes a drop-down menu of locations and topics, and a search facility. Approximately 60 CDs were also distributed to hospital based doctors.

Approximately 16 CDs were distributed to general practitioners. There were problems with the installation of DIP on some general practitioners' computers which affected some aspects of its functionality. All problems were not resolved during the trial, and

293 this affected the way some general practitioners judged the product; eg being unable to minimise the DIP window meant that general practitioners were less likely to use the application.

294

Chapter 5

Evaluation and Feedback

295 EVALUATION AND FEEDBACK

INTRODUCTION It is recognised that any dissemination of clinical practice guidelines should include an evaluation of the quality and acceptability of the guidelines, the dissemination and implementation methodology, and whether the guidelines make any difference to clinical practice 31. Only then can it be known whether guidelines are worth developing, disseminating and implementing. The evaluation should include various components, including the assessment of the dissemination process itself, and the assessment of whether the guidelines contribute to change in clinical practice.

Broadly, the evaluation aimed at measuring whether 'marketing' the pathways intensively with clinicians in three departments of Royal Perth Hospital (RPH) resulted in: • Increased frequency of access to the pathways. • Improved alignment between knowledge of diagnostic imaging and DIP. • Improved alignment between actual requesting behaviour and DIP.

Evaluation also aimed at documenting the following: • Clinician perception of the usefulness of DIP in clinical practice. • Clinician perception of the utility of the electronic environment. • Barriers to the use of DIP. • Suggestions for further development.

METHODOLOGY Reference was made to the National Health & Medical Research Council's (NHMRC) guide to the development, implementation and evaluation of clinical practice guidelines 30. Liaison with the School of Population Health, University of Western Australia was also undertaken. The evaluation had two phases; Assessment 1 at the onset of intensive marketing, Assessment 2 following a period intensive marketing. The data were extracted from RPH information systems to measure access to the DIP product via the intranet.

296 The knowledge of diagnostic imaging was assessed with a multiple-choice questionnaire (APPENDIX 1) completed before (ASSESSMENT 1) and after the trial dissemination of DIP (ASSESSMENT 2). Seven common clinical presentations were described, 36 diagnostic imaging statements were provided, and respondents were required to mark each statement as 'true', 'false' or 'unsure'. The correct answers corresponded with DIP recommendations. The correct responses were summed and expressed as per cent of 36 items.

The requesting behaviour was assessed in the Emergency Department at RPH only. A record was obtained of all admissions on a single day before (ASSESSMENT 1) and after the trial dissemination (ASSESSMENT 2). For each admission, the presenting symptom and provisional diagnosis was obtained from the Emergency Department Information System (EDIS). Diagnostic imaging examinations for each admission were obtained from the Medical Imaging Information System (MIIS). An imaging specialist assessed the information and rated each admission in the following categories: 'imaging compliant with DIP', 'appropriate imaging but topic not included in DIP', 'imaging not compliant with DIP', 'insufficient information to permit a rating'.

The clinicians’ perception was assessed with qualitative questionnaires. For ASSESSMENT 1 the questionnaire contained five sections (APPENDIX 2): • 'Awareness and knowledge' - two questions, each with sub-items, regarding awareness and use of DIP product. • 'Attitude to guidelines' - seven questions, each with sub-items, relating to perceived need for, confidence in, and barriers to use of DIP. • 'Attitude to electronic format' - three questions, each with sub-items, relating to functionality of electronic environment. • 'Professional support' - one question with sub-items relating to support from colleagues in the use of DIP. • 'Comments' - a section for any further comments and suggestions.

For (ASSESSMENT 2), some questions were repeated and new questions were also asked. The questionnaire contained five sections (APPENDIX 3): • 'Awareness and knowledge' - four questions, each with sub-items regarding awareness and use of DIP.

297 • 'Attitude to guidelines' - seven questions, each with sub-items, relating to perceived need for, confidence in, and barriers to use of DIP. • 'Attitude to electronic format' - three questions, each with sub-items, relating to functionality of electronic environment. • 'Professional support' - one question with sub-items relating to support from colleagues in the use of DIP. • 'Comments' - a section for any further comments and suggestions.

Questionnaires for ASSESSMENT 1 (APPENDICES 1 and 2) were distributed, completed and collected at the meetings of the three Departments in July 2003. An incentive to complete the questionnaires was provided; the name supplied on each completed questionnaire was entered into a draw for prizes which included a digital camera. The list of names also provided the means for following up the participants for the second assessment. Information on diagnostic imaging requests for all admissions to the Emergency Department on 22 June 2003 was also gathered.

Questionnaires for ASSESSMENT 2 (APPENDICES 1 and 3) were sent as labelled packages to the three Departments on 23 September 2003 for circulation to the original participants, approximately two months after the intensive 'launch' of DIP at the Departmental meetings. A gesture of goodwill was provided in the form of complementary refreshments included with the assessment package. A covering letter explained the procedure for completing the questionnaires. Access to DIP while completing the questionnaires was permitted. A 'Frequently Asked Questions' sheet was provided. A sense of urgency was implied by setting an early return date (26 September) and an addressed envelope. Information on diagnostic imaging requests for all admissions to the Emergency Department on 22 September 2003 was also gathered.

The evaluation methodology is summarised in Table 2.

298 TABLE 2 Evaluation methodology for hospital-based clinicians and general practitioners PARAMETER HOSPITAL-BASED CLINICIANS GENERAL PRACTITIONERS Alignment between Multiple choice questionnaire Multiple choice questionnaire knowledge of • seven common clinical presentations • seven common clinical diagnostic imaging and 36 diagnostic imaging statements presentations and 35 diagnostic and DIP • requesting clinicians marked each imaging statements statement as 'true', 'false' or 'unsure' • requesting clinicians marked each • correct responses were summed and statement as 'true', 'false' or 'unsure' expressed as per cent of 36 items • correct responses were summed and expressed as per cent of 35 items Alignment between Record obtained of all admissions on a GPs completed a form for each of 20 actual requesting single day to the Emergency Department. patients seen in their clinical practice practice and DIP For each admission, the presenting who required diagnostic imaging, symptom, provisional diagnosis, and providing details of presenting diagnostic imaging examination obtained. symptoms/preliminary diagnosis, Imaging specialist rated each admission in duration of symptoms, relevant physical the following categories: signs, previous imaging, imaging • 'imaging compliant with DIP' currently ordered. Imaging specialist • 'appropriate imaging but topic not assessed the information and rated each included in DIP' consultation in one of the following • 'imaging not compliant with DIP' categories: • 'insufficient information to rate' • 'compliant with DIP' • 'not compliant with DIP' Requesting Qualitative questionnaire which included Qualitative questionnaires which clinicians' items relating to: included items relating to: judgement of • 'awareness and knowledge' - awareness • 'awareness and knowledge' - usefulness of DIP, and use of DIP knowledge of diagnostic imaging, barriers to use and • 'attitude to guidelines' - perceived need confidence in requesting, suggestions for for, confidence in, and barriers to use knowledge of DIP improvement • 'attitude to electronic format' - • 'attitude to guidelines' - perceived functionality of electronic environment need for, confidence in, and • 'comments' - a section for further barriers to use comments and suggestions • 'attitude to electronic format' • 'comments'

299 RESULTS

Hospital-based clinicians A total of 54 hospital based doctors were enlisted in the intensive marketing of DIP and completed all components of Assessment 1. However, only 27 completed all aspects of Assessment 2.

DIP was judged to be useful in the following circumstances: • choosing between potentially useful examinations • more experienced staff unavailable for consultation • unfamiliar or problematic clinical presentations • resolving uncertainty arising from conflicting opinion • justifying the choice of particular examinations • justifying not ordering examinations

The key results from the evaluation are summarised in Table 3.

300 TABLE 3 Summary of key results comparing Assessment 1 to Assessment 2 with respect to hospital-based clinicians PARAMETER MEASURE ASSESSMENT 1 ASSESSMENT 2 Alignment between Mean per cent correct knowledge of diagnostic responses on the multiple 71 79 imaging and DIP choice questionnaire Alignment between actual Per cent of emergency requesting practice and DIP admissions with 'imaging not 7 1 compliant with DIP' Awareness and knowledge Per cent of respondents of DIP identifying where to access 19 85 DIP Awareness and knowledge Per cent of respondents using 15 63 of DIP DIP Per cent of respondents giving a high rating to ease 11 67 of use of DIP Attitude to guidelines Per cent of respondents having confidence that DIP 69 85 is up-to-date Per cent of respondents having confidence that DIP 61 85 is comprehensive Per cent of respondents describing barriers to use of 78 74 DIP Attitude to electronic format Per cent of respondents considering elements of the 72 59 electronic format inadequate Per cent of respondents suggesting improvement to 15 19 the electronic format Other comments Per cent of respondents providing general comments 20 30 and suggestions

Respondents identified some 'professional' barriers to the use of DIP in clinical decision-making, for example:

301 • senior and experienced staff are the primary determiners of which examinations are requested • specialists know what tests they want and don't rely on DIP

They also identified 'technology' barriers, for example: • computers not available where and when decisions are made • available computers are too slow • insufficient time available to refer to DIP

Various suggestions were made for improvements to the clinical and academic content, for example: • include abstracts of referenced papers • add examples of diagnostic images to illustrate abnormalities • more information on imaging processes and imaging modalities The above suggestions have subsequently been included in the later version of the Diagnostic Imaging pathways.

Suggestions were also provided regarding the electronic environment, for example: • make available on 'Palm' or other wireless device • more and faster computers • reduce the size of flow-charts to reduce the need for scrolling • minimise time to access DIP

General practitioners A total of nine general practitioners were enlisted in the intensive marketing of DIP and completed all components of Assessment 1. However, only five completed all aspects of Assessment 2. This low number of participants makes it difficult to be confident about the generality of results.

DIP was judged to be useful in the following circumstances: • uncommon and unfamiliar conditions • patient reassurance • source of high level knowledge, a reference tool for the latest available and most effective test • support for my decisions

302

The key results from the evaluation are summarised in Table 4.

TABLE 4 Summary of key results comparing Assessment 1 to Assessment 2 with respect to general practitioners PARAMETER MEASURE ASSESSMENT 1 ASSESSMENT 2 Alignment between Mean per cent correct knowledge of diagnostic responses on the multiple 72 78 imaging and DIP choice questionnaire Alignment between actual Per cent of patients with requesting practice and DIP 'imaging not compliant with 13 8 DIP'

Variation between Assessment 1 and Assessment 2 qualitative questionnaires make it difficult to achieve direct comparisons as reported for hospital-based clinicians (Table 3).

The key results from Assessment 2 are summarised in Table 5. TABLE 5 Summary of key results from Assessment 2 qualitative questionnaires with respect to general practitioners PARAMETER ASSESSMENT 2 Awareness and knowledge of All respondents demonstrated a working knowledge of DIP DIP Attitude to guidelines All respondents were confident that DIP was up-to-date All respondents provided suggestions for improvement to the clinical and academic content Attitude to electronic format All respondents found DIP quick and easy to access and use 33 per cent of respondents provided suggestions for improvement to the electronic environment Other comments All respondents provided general comments and suggestions

Respondents identified 'professional' barriers to using DIP, for example: • patient expectations often influence imaging decisions

303 • difficult to find the required pathway • insufficient pathways • not enough evidence to make me choose the pathway • anxious that if I followed the pathway I might miss a diagnosis

They also identified 'technology' barriers, for example: • using electronic guides eats into time especially during consultation • hardware not available • lack of reminder or prompt • needs to be more user friendly

Suggestions for improvement to the clinical and academic content included: • more pathways relevant to general practice • classify pathways according to anatomy or symptom and not the current hybrid • include information about costs

Suggestions regarding the electronic environment included: • integrate the product with other GP packages • incorporate into on-line learning program • provide access over the Internet

304

Chapter 6

Discussion

305 DISCUSSION

Clinical and academic content We maintain the view that there will never be a 'final' version of DIP; it requires constant review and update based on: • clinical practice and feedback • local circumstances and availability of medical imaging diagnostic services • published evidence • advances in the application of medical imaging to diagnosis

While the content of the pathways was well accepted generally, there is scope for improvement. Future directions include: • Act on feedback from the current trial e.g. image gallery and information on various imaging modalities has been included in the later version of the Diagnostic Imaging Pathways. Hot links to Pubmed for higher grade of evidence have been provided in subsequent versions. • liaise with stakeholders representing requestors and providers to define requirements for • additional content, including information, images, references, abstracts, examination costs, etc • additional pathways • a 'consumer' version, including a companion for DIP to enable clinicians to print information for patients. This is now in the early stages of development. • review and incorporate new evidence from the literature • prepare a new edition of the pathways

Electronic environment While the electronic format was well accepted, it was clear that the major barriers to the implementation of DIP stemmed from information technology issues. DIP needs to be available quickly and easily, at the time and place where clinical decisions are being made (eg, on a ward-round at the bedside, or during a consultation with a patient). Ideally, reference to DIP should be made less 'optional' and more 'mandatory'; eg development of a decision-support system by linking DIP to an electronic process of

306 ordering diagnostic examinations which provides alerts if a request is 'non-compliant'. Future directions include: • act on feedback from the current trial • liaise with stakeholders representing requestors and providers to define requirements for improved functionality, accessibility in various clinical settings, customisation, more on-line guidance on access, navigation and use • plan changes to the architecture to achieve easier updating of the content, better deployment in various IT environments, linkage to other information systems, facilitation of future licensing requirements, collection of utilisation data for evaluation and marketing purposes • revise the electronic environment

Dissemination and implementation The dissemination methodologies were found to be broadly satisfactory. However, there are reports of doctors within the hospital still being unaware of DIP despite the following: • availability of the pathways on the local area network for at least three years • obvious placement of an icon on all computer 'desk-tops' • many activities to raise general awareness • intense 'marketing' activity in three large Departments

This is a prompt to reflect on the vigorous effort that would be required to raise awareness and engage clinicians in environments where there is no history of previous engagement or use of DIP.

The goal is for clinicians to request a diagnostic examination according to DIP, unless there are cogent reasons for doing otherwise. DIP needs to be embedded in the consulting/decision-making process. As outlined above, information technology enhancements may improve uptake and implementation. However, we feel that incentives may be required to achieve highest rates of compliance; eg tangible rewards for compliance and/or higher costs associated with non-compliant imaging.

Evaluation The finding that knowledge of diagnostic imaging and requesting behaviour tended to become more aligned with DIP following a period of intense marketing is encouraging.

307 Although the absence of control groups negates the possibility of fully ascribing any change to utilisation of DIP, qualitative data from questionnaires, which implicate DIP as an agent of change, include the following: • increased awareness, knowledge, and utilisation of DIP • increased confidence in the currency and comprehensiveness of the pathways • referral to specific circumstances in which the pathways were found to be useful

Longer term follow-up is required to determine whether requesting behaviour remains aligned with DIP following the cessation of intensive marketing.

308 CONCLUSIONS

Systematic review of literature and input and feedback from various clinicians and radiologists led to the development of consensus based Diagnostic Imaging Pathways supported by evidence. These pathways are a valuable decision support tool and are a definite step towards incorporating evidence based medicine in patient management. The clinical and academic content of Diagnostic Imaging Pathways was found to be of practical use to a wide range of clinicians in hospital and general practice settings. It is source of high level knowledge; a reference tool for the latest available and most effective imaging test for a particular clinical problem. In addition, it is an educational tool for medical students, junior doctors, medical imaging technologists, and allied health care personnel. It can form a part of Continuing Medical Education for General Practitioners and specialist clinicians.

The electronic environment developed for DIP and the method of delivery provided a satisfactory medium for dissemination. Getting Diagnostic Imaging Pathways implemented in the clinical setting required vigorous effort. Knowledge of diagnostic imaging and requesting behaviour tended to become more aligned with DIP following a period of intensive marketing. There is scope for improving the content and the electronic environment, and achieving better integration into patient consultation and clinical decision-making processes. Tangible incentives may be required to achieve highest rates of compliance with DIP recommendations.

309 REFERENCES

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14. Grimshaw JM, Russell IT. Effect of clinical guidelines on medical practice: a systematic review of rigorous evaluations. Lancet 1993; 342: 1317-1322.

310 15. Friedenberg R. Algorithms: the new math in medicine. Radiology 1994; 192: 47A- 49A.

16. Imaging Guidelines, Fourth edition. The Royal Australian and New Zealand College of Radiologists, 2001.

17. Matowe L, Ramsay CR, Grimshaw JM, et al. Effects of mailed dissemination of the Royal College of Radiologists’ guidelines on general practitioner referrals for radiography: a time series analysis. Clinical Radiology 2002; 57: 575-578.

18. Glaves J. The use of radiological guidelines to achieve a sustained reduction in the number of radiographic examinations of the cervical spine, lumbar spine and knees performed by GPs. Clinical Radiology 2005; 60: 914-920.

19. Stuart PJ, Crooks S, Porton M. An interventional program for diagnostic testing in the emergency department. Med J Aust 2002; 177: 131-134.

20. Mendelson RM, Blake M. Diagnostic Imaging Pathways in Adults (second edition). Imaging Division, Royal Perth Hospital, Western Australia.

21. The Evidence-Based Radiology Working Group. Evidence-based Radiology: A new approach to the practice of radiology. Radiology 2001; 220: 566-575.

22. Roberts CJ. Towards the more effective use of diagnostic radiology. A review of the work of the RCR Working Party on the More Effective Use of Diagnostic Radiology 1976-1986. Clinical Radiology 1988; 39: 3-6.

23. RCR Working Party. A multi-centre audit of hospital referral for radiological investigation in England and Wales. BMJ 1991; 303: 809-812.

24. RCR Working Party. Influence of the Royal College of Radiologists’ Guidelines on hospital practice: a multi-centre study. BMJ 1992; 304: 740-743.

25. Roberts CJ. The RCR Multi-Centre Guidelines Study. Implications for clinical practice. Clinical Radiology 1992; 45: 365-368.

26. National Centre for Biomedical Information. Pubmed: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi [9 September 2004]

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311 29. Stiell IG, Greenberg GH, McKnight RD et al. A study to develop clinical decision rules for the use of radiography in acute ankle injuries. Ann Emerg Med 1992; 21: 384-390.

30. National Health and Medical Research Council. A guide to the development, implementation and evaluation of clinical practice guidelines. Canberra: Commonwealth of Australia, 1999.

31. NHS Research and Development, Centre for Evidence-Based Medicine. CAT bank topics: Levels of Medicine. Available at: cebm.jr2.ox.ac.uk/eboc/eboclevels.html.

312

Appendices

313 APPENDIX 1

Multiple-choice questionnaire provided to hospital clinicians before (ASSESSMENT 1) and after (ASSESSMENT 2) the trial dissemination, measuring correspondence between knowledge of diagnostic imaging and DIP recommendations. The 'correct' answers are shaded.

In patients with blunt thoracic injury:

1) Any mediastinal haematoma on CT should lead to aortography T / F / Unsure

2) A normal supine chest radiograph in a patient with low clinical suspicion has a high negative predictive value in excluding aortic injury T / F / Unsure

3) A haematoma on CT around the thoracic aortic branches or in the periaortic region should prompt aortography T / F / Unsure

4) Aortography is the “gold-standard” in the diagnosis of aortic trauma T / F / Unsure

Plain abdominal radiographs are indicated in: 1) suspected acute cholecystitis T / F / Unsure 2) a young patient with acute right iliac fossa pain T / F / Unsure 3) patients with haematemesis / melaena T / F / Unsure 4) suspected bowel obstruction T / F / Unsure 5) suspected renal colic T / F / Unsure

In patients with clinical evidence of acute pancreatitis, the following are indications for early CT: 1) To exclude gall stones T / F / Unsure 2) A patient failing to respond or deteriorating after admission T / F / Unsure

314 3) Diagnostic uncertainty T / F / Unsure 4) Routinely, as a baseline T / F / Unsure 5) Clinically severe pancreatitis T / F / Unsure

In an elderly patient presenting acutely with clinical features and plain abdominal x-ray suggestive of large bowel obstruction, the following investigations are appropriate:

1) CT of the abdomen T / F / Unsure 2) Limited contrast enema T / F / Unsure 3) barium meal and follow-through T / F / Unsure 4) double-contrast barium enema T / F / Unsure 5) sigmoidoscopy T / F / Unsure

A 50 year old woman has a history of surgery and radiotherapy for cervical carcinoma and presents with clinical features and abdominal x-ray consistent with high-grade small bowel obstruction. Which of the following is the most appropriate investigation:

1) No imaging T / F / Unsure 2) Barium meal and follow-through T / F / Unsure 3) CT of abdomen T / F / Unsure 4) Barium enema T / F / Unsure

315 5) Small bowel enema (enteroclysis) T / F / Unsure

The following statements regarding the diagnosis of pulmonary embolism (PE) are true: 1) In a patient with a high clinical probability of a “major” PE, treatment should be delayed until imaging confirms the diagnosis T / F / Unsure

2) Doppler US of the lower limbs is the initial investigation of choice T / F / Unsure

3) In a stable patient with a normal chest x-ray ,clinical suspicion of PE and no contraindication to anticoagulation, investigation should be performed immediately, even out-of-hours. T / F / Unsure

4) A normal V/Q scan effectively excludes a clinically significant PE T / F / Unsure

5) A stable patient with a high probability V/Q scan and high clinical Suspicion requires further imaging for confirmation prior to treatment T / F / Unsure

6) Indications for an IVC filter include: a. Routinely in patients with massive PE T / F / Unsure b. Patients with PE and a contraindication to anticoagulation T / F / Unsure c. Recurrent PE despite adequate anticoagulation T / F / Unsure

In a patient with an acute stroke:

1) CT is performed initially to exclude intracranial haemorrhage T / F / Unsure

2) A non-contrast enhanced CT scan is a highly sensitive test for early detection of ischaemic changes (within 24 hours) T / F / Unsure

3) A haemorrhagic infarct should prompt a search for a source of emboli T / F / Unsure

4) Diffusion-weighted MRI is superior to conventional MRI and CT in T / F / Unsure detecting ischaemia in patients with stroke in the first 24 hours of symptoms

316

APPENDIX 2

Qualitative questionnaire provided to hospital clinicians before the trial dissemination (ASSESSMENT 1), assessing perception of need for and utility of DIP. The items have been numbered consecutively in italics to assist with cross referencing to APPENDIX 3.

SECTION 1: AWARENESS & KNOWLEDGE QUESTIONS

(1.1) 1. Are you aware of the Diagnostic Imaging Pathways web site? (Tick appropriate response)

YES – go to Question 2 NO – go to Question 3 UNSURE – go to Question 3

(1.2) Please list some places where you can access the site.

† I don’t know of any places 1.______2.______3.______4.______

(1.3) How familiar are you with the Diagnostic Imaging Pathways tool?

Quantitative Rating: (least) 1 2 3 4 5 (most) (Circle the appropriate level)

(2.1) 2. Have you used the Diagnostic Imaging Pathways tool yet? (Tick appropriate response)

YES NO

317 (2.2) Rank the ease of use of the Imaging Pathways tool format.

Quantitative Rating: (least) 1 2 3 4 5 (most) (Circle the appropriate level)

318

SECTION 2: ATTITUDE QUESTIONS

(5.1) 3. Do you think an Imaging Pathways tool could assist you when selecting and requesting an imaging examination? (Tick appropriate response)

YES – go to Question 4 NO – go to Question 5 UNSURE – go to Question 5

(5.2) 4. Describe circumstances where it could be valuable? ______

Indicate how useful you think an Imaging Pathways tool would be.

(5.3) Quantitative Rating: (least) 1 2 3 4 5 (most) (Circle the appropriate level)

(6.1) 5. Would you be confident that a hospital developed electronic format pathways tool is up-to-date? (Circle appropriate response)

YES NO UNSURE

(6.2) Rate how confident you are likely to be.

Quantitative Rating: (least) 1 2 3 4 5 (most) (Circle the appropriate level)

(7.1) 6. Would you be confident that a hospital developed electronic format pathways tool is comprehensive? (Circle appropriate response)

YES NO UNSURE

(7.2) Rate how confident you are likely to be.

Quantitative Rating: (least) 1 2 3 4 5 (most) (Circle the appropriate level)

319 (8.1) 7. What, if any, perceived barriers do you anticipate to utilising an imaging pathways tool? (access, time, user-friendliness, lack of support, other) ______

(8.2) Indicate how important it is to decrease obstacles/barriers to using this tool.

Quantitative Rating: (least) 1 2 3 4 5 (most) (Circle the appropriate level)

(9.1) 8. Suggest features that an imaging pathways decision support tool should possess? ______

(9.2) Assign a level of importance to these suggested features.

Quantitative Rating: (least) 1 2 3 4 5 (most) (Circle the appropriate level)

(10.1) 9. Would you use an imaging guideline tool for patients in whom you consider an imaging examination/s? (Circle appropriate response)

YES NO SOMETIMES

(10.2) If yes, describe how utilising such a tool may influence/modify your requesting practices? ______

(10.3) To what degree do you think utilising this tool may influence/modify your requesting practices?

Quantitative Rating: (least) 1 2 3 4 5 (most) (Circle the appropriate level)

320 (11.1) 10. What methods do you use to decide which imaging examination is the most appropriate to request? ( Eg: physical examination of the patient alone [+/-] advice from radiologists, other doctors/nurses/, etc.) ______

(11.2) How much do you rely on these methods to assist in your imaging request decisions?

Quantitative Rating: (least) 1 2 3 4 5 (most) (Circle the appropriate level)

321

SECTION 3: ELECTRONIC FORMAT

(13.1) 11. What specific elements of a proposed electronic format would you consider to be valuable? † Decision tree style imaging flow charts † Overview of imaging modalities † Hyperlinks to further information † List of further reading † Other (please specify) ______

(13.2) Rank how valuable you consider these elements to be. Quantitative Rating: (least) 1 2 3 4 5 (most) (Write level in box beside choice/s)

(14.1) 12. What specific elements of an electronic format do you find inadequate/ineffectual? † I have limited access to computers † I am not confident when using computer based programs † It takes too long to load the program † Other (please specify) ______

(14.2) Rate how inadequate/ineffectual these elements are.

Quantitative Rating: (least) 1 2 3 4 5 (most) (Write level in box beside choice/s)

(15.1) 13. What would you like to improve about the electronic format of the pathways tool? ______

322

(15.2) Indicate how important this change is to your (continued) use of the Imaging Pathways tool. Quantitative Rating: (least) 1 2 3 4 5 (most) (Circle the appropriate level)

323

SECTION 4: PROFESSIONAL SUPPORT

(16.1) 14. Do you find that your colleagues support your use of the Imaging Pathways tool at work?

YES NO SOMETIMES

(16.2) If yes, please describe ______

(16.3) Specify the level of support you receive to consult this decision support tool at work.

Quantitative Rating: (least) 1 2 3 4 5 (most) (Circle the appropriate level)

SECTION 5: GENERAL COMMENTS

(17.1) Please add any comments and suggestions in the space provided below.

______

324

APPENDIX 3

Qualitative questionnaire provided to hospital clinicians after the trial dissemination (ASSESSMENT 2), assessing perception of need for and utility of DIP. The items have been numbered consecutively in italics to assist with cross referencing to APPENDIX 2.

SECTION 1: AWARENESS & KNOWLEDGE QUESTIONS

(1.2) 1. Now that you are aware of the Diagnostic Imaging Pathways tool please list some places where you may gain access to it.

† I don’t know of any places 1. ______2.______3.______4.______

(1.3) How familiar are you with the Diagnostic Imaging Pathways tool?

Quantitative Rating: (least) 1 2 3 4 5 (most) (Circle the appropriate level)

(2.1) 2. Have you used the Diagnostic Imaging Pathways tool yet?

YES NO

(2.2) Rank the ease of use of the Diagnostic Imaging Pathways tool.

Quantitative Rating: (least) 1 2 3 4 5 (most) (Circle the appropriate level)

325 (3.1) 3. Please describe in steps, from opening the program to viewing the flowchart, how you access the imaging pathway for acute lower back pain: ______

(3.2) Rate how often you refer to the Imaging Pathways when considering an imaging examination request.

Quantitative Rating: (least) 1 2 3 4 5 (most) (Circle the appropriate level)

(4.1) 4. Now that you have the flowchart open, how would you find out details about a particular imaging examination recommended in the flowchart? ______

SECTION 2: ATTITUDE QUESTIONS

(5.1) 5. Do you think the Imaging Pathways tool can assist you in making decisions regarding the selection and requesting of imaging examinations? (Tick appropriate response)

YES NO UNSURE

(5.2) Describe, in the space below, circumstances where the pathways are valuable? ______

(5.3) Indicate how useful the Imaging Pathways tool is. 326

Quantitative Rating: (least) 1 2 3 4 5 (most) (Circle the appropriate level)

(6.1) 6. Do you have confidence that the pathways are up-to-date? (Circle appropriate response)

YES NO UNSURE

(6.2) Rate how confident you are.

Quantitative Rating: (least) 1 2 3 4 5 (most) (Circle the appropriate level)

(7.1) 7. Do you have confidence that the pathways are comprehensive? (Circle appropriate response)

YES NO UNSURE

(7.2) Rate how confident you are.

Quantitative Rating: (least) 1 2 3 4 5 (most) (Circle the appropriate level)

(8.1) 8. What, if any, perceived barriers do you currently experience to utilising the pathways tool? (for example: access, time, user-friendliness, lack of support etc.) ______

(8.2) Indicate how important it is to decrease these obstacles/barriers to using this tool. Quantitative Rating: (least) 1 2 3 4 5 (most) (Circle the appropriate level)

(9.1) 9. Suggest improvements to the features / content of the Imaging Pathways tool. ______

327

(9.2) Assign a level of importance to your suggested improvement/s.

Quantitative Rating: (least) 1 2 3 4 5 (most) (Circle the appropriate level)

(10.1) 10. Do you currently employ Diagnostic Imaging Pathways as a guideline when considering an imaging examination/s for your patients? (Circle appropriate response)

YES NO SOMETIMES

(10.2) If yes, describe below how using the tool has influenced / modified your requesting practices ______

(10.3) Indicate the impact that utilising Imaging Pathways has had on your diagnostic imaging, requesting practices.

Quantitative Rating: (least) 1 2 3 4 5 (most) (Circle the appropriate level)

(12.1) 11. When determining the most appropriate imaging examination, does utilisation of the pathways complement or clash with your existing methods? (Circle appropriate response)

COMPLIMENT CLASH BOTH NEITHER

(12.2) List below those methods you use to decide which imaging examination is the most appropriate to request? (eg: physical examination of the patient alone, advice from other doctors/nurses/radiographers, etc.) ______

(12.3) Indicate your level of reliance on these methods.

Quantitative Rating: (least) 1 2 3 4 5 (most) (Circle the appropriate level) 328

SECTION 3: ELECTRONIC FORMAT

(13.1) 12. Specify elements of the electronic format that you find valuable?

† Decision tree style imaging flow charts † Overview of imaging modalities † Hyperlinks to further information † List of further reading † Other (please specify)______

(13.2) Rank how valuable you consider these elements to be.

Quantitative Rating: (least) 1 2 3 4 5 (most) (Write level in box beside choice/s)

(14.1) 13. Specify elements of the electronic format that you find inadequate / ineffectual?

† I have limited access to computers † I am not confident when using computer based programs † It takes too long to load the program † Other (please specify) ______

(14.2) Rate how inadequate / ineffectual these elements are. Quantitative Rating: (least) 1 2 3 4 5 (most) (Write level in box beside choice/s)

(15.1) 14. What would you like to improve about the electronic format of the pathways tool?

329 ______

(15.2) Indicate how important this change is to your continued use of the Imaging Pathways tool.

Quantitative Rating: (least) 1 2 3 4 5 (most) (Circle the appropriate level)

330

SECTION 4: PROFESSIONAL SUPPORT

(16.1) 15. Do colleagues support your use of the Imaging Pathways tool at work? (Circle appropriate response)

YES NO SOMETIMES

(16.2) Please describe ______

(16.3) Specify the level of support you receive to consult the Imaging Pathways tool at work.

Quantitative Rating: (least) 1 2 3 4 5 (most) (Circle the appropriate level)

SECTION 5: GENERAL COMMENTS

(17.1) Please add any comments and suggestions in the space provided below.

______

331

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