DOCSLIB.ORG

Comparison of Intravenous Digital Subtraction Angiography with Radionuclide Ventilation-Perfusion Lung Scanning in Patients with Suspected Pulmonary Embolism

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Comparison of Intravenous Digital Subtraction Angiography with Radionuclide Ventilation-Perfusion Lung Scanning in Patients with Suspected Pulmonary Embolism Thorax: first published as 10.1136/thx.40.8.576 on 1 August 1985. Downloaded from Thorax 1985;40:576-580 Comparison of intravenous digital subtraction angiography with radionuclide ventilation-perfusion lung scanning in patients with suspected pulmonary embolism KC FLINT, N McI JOHNSON, A MANNHIRE, P DAWSON, S GEORGE, PJ ELL From the Medical Unit, the Department ofRadiology, and the Institute of Nuclear Medicine, Middlesex Hospital, London ABSTRACT Fifty one patients with suspected pulmonary embolus were studied by radionuclide ventilation-perfusion scanning and intravenous digital subtraction pulmonary angiography. In 31 patients the results of both investigations were reported as negative and in a further 11 both results were reported as positive, giving a concordance rate of 82.3%. In nine patients there was disagreement between the two investigations and an attempt to resolve this difference on the basis of clinical data was made. On this basis digital subtraction angiography would have falsely classified three patients as not having an embolus who were correctly identified by radioisotope scanning. Angiography would, however, have correctly classified four patients misclassified by ventilation-perfusion scanning. The relative merits of digital subtraction angiography and copyright. radionuclide lung scanning are discussed. Confirmation of the diagnosis of pulmonary embol- Digital subtraction angiography combines digital http://thorax.bmj.com/ ism remains a common but difficult clinical prob- imaging with computer subtraction techniques to lem.' 2 Accurate and early diagnosis is important provide arterial images after intravenous injection because of the considerable morbidity and mortality of contrast medium.'3 This technique will provide associated with both untreated embolisation34 and images of the pulmonary circulation after injection inappropriate anticoagulant treatment.56 of contrast medium via a central venous catheter.'4 Radionuclide pulmonary perfusion scans are sen- It therefore avoids the additional risk of cardiac sitive but lack specificity. Many chronic cardiac and catheterisation, which is responsible for most of the pulmonary disorders result in perfusion abnor- complications and the deaths that follow conven- malities indistinguishable from pulmonary embol- tional pulmonary angiography. In 31 patients who on September 30, 2021 by guest. Protected ism.7'8 With the addition of ventilation studies were subsequently investigated by pulmonary specificity can be improved, but in the absence of a angiography'5 digital subtraction angiography cor- characteristic pattern of mismatched defects diag- rectly identified 12 as having suffered pulmonary nostic accuracy may be low.9 II Pulmonary angiogra- embolism and excluded embolic disease in a further phy therefore continues to be the most specific test 18. The result was falsely positive on only one occa- for the detection of pulmonary emboli. The associ- sion. In another study'6 the sensitivity of digital sub- ated morbidity (1%) and mortality (0.5%) have, traction angiography after experimentally induced however, precluded its use in most patients and it is gelfoam embolisation in dogs was found to be 100% usually reserved for those with life threatening com- if defects in parenchymal staining during the capil- plications in whom aggressive treatment is being lary phase were taken into account. Even if the more considered." 12 specific criteria of demonstrating vessel cut off and intravascular filling defects are used, the method Address for correspondence: Dr N Johnson, Middlesex Hospital, compares favourably in sensitivity (75%) with London WlN 8AA. (Reprints will not be available.) radionuclide lung scanning. Accepted 22 February 1985 We have compared intravenous digital subtrac- 576 Comparison of intravenous digital subtraction angiography with radionuclide lung scanning 577 Thorax: first published as 10.1136/thx.40.8.576 on 1 August 1985. Downloaded from tion angiography with radionuclide ventilation- defects accompanied by a normal chest radiograph perfusion lung scanning, which is the most fre- and normal ventilation, and where perfusion defects quently used investigative technique in patients with were substantially larger than any corresponding suspected pulmonary embolism. radiographic abnormality with normal ventilation. Methods DIGITAL SUBTRACTION ANGIOGRAPHY Digital subtraction angiography was performed with Fifty one consecutive patients were studied. All a Technicare DR960 apparatus, which has a maxi- were referred to the Institute of Nuclear Medicine at mum field size of 22.5 cm. The framing rate used the Middlesex Hospital with the suspected diagnosis was 1.25 per second with a matrix of 512 x 512 of pulmonary embolism and gave informed consent pixels. to additional investigation. Sixteen were hospital An arm vein was selected in the antecubital fossa inpatients, 14 were outpatients and 21 were referred and a 5 Fr catheter with side and end holes was from outlying hospitals. The mean age of this popu- introduced by the Seldinger technique after local lation was 52 years, 26 were female, 21 were smok- anaesthesia. The catheter was advanced centrally ers and eight had spirometric evidence of airflow until the tip was situated in the superior vena cava. obstruction (FEV,/FVC ratio < 70%). On one occasion no suitable arm vein was available In all cases ventilation-perfusion lung scans and and the femoral vein was punctured and the catheter digital subtraction angiograms were performed tip placed in the inferior vena cava. Forty millilitres within 24 hours of each other. Each was reported of iohexol (Omnipaque 300) 300 mg iodine/ml were independently in the presence of a current chest injected at 25 ml per second. The patient was radiograph but without knowledge of specific clini- instructed to hold his breath in inspiration and cal details or the result of the alternative investiga- frames of the arterial, capillary, and venous phases tion. Digital subtraction angiograms were were recorded for later examination. reported in groups of 15-20 by two radiologists A posteroanterior view of the right lung was (AM and PD) in combination and ventilation- obtained followed by a 25° left anterior oblique view perfusion lung scans were reported in similar groups of the left lung, a 22.5 cm field being used. Further copyright. by two nuclear medicine physicians (SG and PE). oblique views of suspicious areas were obtained All patients were interviewed by an independent after a further injection of contrast material with a clinician (KF) and clinical features recorded. 15 cm field for elucidating specific problems. Our preliminary studies showed three characteris- VENTILATION-PERFUSION LUNG SCANS abnormalities in digital subtraction angiograms: tic http://thorax.bmj.com/ Ventilation study (1) Defects in the perfusion image during the capil- A Nuclear Associates xenon lung function unit was lary filling phase. During this phase of the digital used. Each patient inhaled 222 MBq (6 mCi) xenon subtraction angiogram, parenchymal staining is pro- 133 and images were obtained of the wash in, nounced and areas of oligaemia are easily seen. Such equilibrium, and wash out phases. Three wash out defects may correspond to areas of radiographic images were obtained: 0-1 min, 1-3 min, 3-6 min. abnormality (I) or they may not (II)-see figure 1. Increasing image acquisition time during wash out (2) Abrupt termination of pulmonary arteries with increases the sensitivity for gas trapping. All images diminished peripheral perfusion (III). (3) Filling were obtained in a posteroanterior projection. defects visible within the pulmonary arteries on September 30, 2021 by guest. Protected (IV)-figure 2. Perfusion study The last two abnormalities (III and IV), which are We gave albumin macroaggregrates labelled with commonly seen in experimental embolisation of the technetium 99m (140 MBq (4 mCi)) intravenously pulmonary arteries,'5 were taken to be specific for to each patient. Six planar projections were pulmonary embolism. The first type of abnormality acquired-posteroanterior, anteroposterior, right (perfusion defects) may or may not represent pul- and left laterals, and right and left posterior obli- monary emboli. To improve the specificity of such ques. All images were obtained with a gamma cam- defects they were interpreted in conjunction with a era having a large field of view-either a General chest radiograph. Multiple perfusion defects not Electric Maxicamera 400 AT or a Nuclear Enter- corresponding to areas of radiological abnormality prises Mk V LF. (Ilb) were reported as positive for pulmonary Ventilation-perfusion lung scans were reported embolism. Defects corresponding to areas of radio- according to conventional criteria. They were graphic abnormality (I) and single defects which did regarded as positive where there was one or more not correspond to such areas were reported as nega- segmental or two or more subsegmental perfusion tive (IIa). 578 Flint, Johnson, Mannhire, Dawson, George, Ell Thorax: first published as 10.1136/thx.40.8.576 on 1 August 1985. Downloaded from Results The results of the 51 digital subtraction angiograms and ventilation-perfusion lung scans are compared in table 1. In 31 patients the results of both investi- gations were reported negative and in 11 patients both results were reported as positive, giving a con- cordance rate of 82.3%. In nine patients there was disagreement between the two results. The clinical features, digital subtraction
Load more

Recommended publications
  • Central Venous Access with Accelerated Seldinger Technique Versus Modified Seldinger Technique
    Central Venous Access with Accelerated Seldinger Technique versus Modified Seldinger Technique L A N E THAUT , D O , CAPT , M C , USAF SAN ANTONIO MILITARY MEDICAL CENTER CO- AUTHORS: WELLS WEYMOUTH, MD, DANIEL RESCHKE, MD, BRANDEN HUNSAKER,MD Disclosures Expired POWERWAND™ combination device kits were donated by Access Scientific for the express purpose to be used in this study; however, no other contributions were made. We approached Access Scientific to obtain the devices to conduct this study. No financial relationship with Access Scientific. Background Techniques Research and Outcomes Questions Background Air Force SAMMC San Antonio, TX Level 1 Trauma Center 85,000+ patients annually Central Access Common Procedure Approximately 8% of hospitalized patients Multiple indications Large volume fluid or blood product resuscitation Administration of central acting medications Multiple medications simultaneously Trans venous pacing Difficult peripheral access Quick Story What if there was a simpler/quicker way? Intra-osseous? Complications Slower Flow Rate Labs Traditional Central Line Multiple steps/parts Midlines Usually used for extended dwelling lines. Self contained, all in one device. Equivalent and sometimes superior flow rate. Question Will the use of combination devices (midline/POWERWAND™) and the associated accelerated technique reduce the time of CVC placement? VS What is Accelerated Seldinger Technique? Needle, guidewire, dilator, and sheath into one. The device needle is inserted into the target vein under ultrasound guidance and a flash is observed The internal guidewire is then advanced into the vein and snapped into the needle hub. Dilator collar is turned and the dilator and sheath are advanced The dilator hub is disengaged from the needle hub, and the guidewire, dilator, and needle are all removed as a single unit.
    [Show full text]
  • Practice Parameter for the Use of Ultrasound to Guide Vascular Access Procedures
    PRACTICE GUIDELINES AIUM Practice Parameter for the Use of Ultrasound to Guide Vascular Access Procedures I. Introduction he clinical aspects of this parameter were developed collaboratively among the AIUM and other organizations whose members use ultrasound for guidance in vascular T “ ” access procedures (see Acknowledgments ). Recommendations for practitioner requirements, the written request for the examination, procedure documentation, and quality control vary among the organizations and are addressed by each separately. This parameter has been developed by and for clinicians from diverse specialties and practitioner levels who perform vascular access. While vascular access may be performed using external landmarks, point-of-care ultrasound is now increasingly available.1 Appropriately used, ultrasound guidance for vascular access has been shown to improve success rates while reducing iatrogenic injury, the number of needle passes, and infection rates.2 Addition- ally, it may improve patient comfort and satisfaction. This parameter is intended to be evidence based when possi- ble and to include selected references of importance, but it is not meant to be a comprehensive or rigorous literature review, as this has been accomplished elsewhere.3 The intent of this document is to highlight appropriate evidence while also providing a practical, real-world expert consensus from clinicians with diverse back- grounds on the best use and techniques for incorporating ultra- sound into vascular access procedures with the ultimate goal of improving the care of our patients. II. Indications/Contraindications Ultrasound should be used to aid in central venous, peripheral venous, and arterial access procedures.4 When used appropriately by qualified personnel, there are no absolute contraindications to using ultrasound as a procedural adjunct for vascular guidance.
    [Show full text]
  • American Society of Echocardiography Recommendations for Performance, Interpretation, and Application of Stress Echocardiography
    GUIDELINES AND STANDARDS American Society of Echocardiography Recommendations for Performance, Interpretation, and Application of Stress Echocardiography Patricia A. Pellikka, MD, Sherif F. Nagueh, MD, Abdou A. Elhendy, MD, PhD, Cathryn A. Kuehl, RDCS, and Stephen G. Sawada, MD, Rochester, Minnesota; Houston, Texas; Marshfield, Wisconsin; and Indianapolis, Indiana dvances since the 1998 publication of the TABLE OF CONTENTS A Recommendations for Performance and Interpreta- tion of Stress Echocardiography1 include improve- Methodology....................................................1021 ments in imaging equipment, refinements in stress Imaging Equipment and Technique............1021 testing protocols and standards for image interpre- Stress Testing Methods...... ............................1022 tation, and important progress toward quantitative Training Requirements and Maintenance analysis. Moreover, the roles of stress echocardiog- of Competency...... .....................................1023 raphy for cardiac risk stratification and for assess- Image Interpretation......................................1024 ment of myocardial viability are now well docu- Table 1. Normal and Ischemic mented. Specific recommendations and main points Responses for Various Modalities are identified in bold. of Stress........................................................1025 Quantitative Analysis Methods.....................1025 Accuracy...... .....................................................1026 False-negative Studies...... ..............................1026
    [Show full text]
  • Too Many Twos in One Patient: Two Central Venous Catheters, Two
    & Experim l e ca n i t in a l l C Journal of Clinical and Experimental C f a o r d l i a o Chalwade, J Clin Exp cardiolog 2018, 9:9 n l o r g u y o Cardiology DOI: 10.4172/2155-9880.1000605 J ISSN: 2155-9880 Case Report Open Access Too Many Twos in One Patient: Two Central Venous Catheters, Two Routes, Two Hospitals, Two Lost Guidewires, Two Vascular Systems, One Patient Rahul Chalwade* Department of Cardiology, Felix Health Care, Noida, Uttar Pradesh, India *Corresponding author: Rahul Chalwade, Department of Cardiology, Felix Health Care, Noida, Uttar Pradesh, India, Phone: +919717053558; E-mail: [email protected] Received date: September 05, 2018; Accepted date: September 10, 2018; Published date: September 17, 2018 Copyright: © 2018 Chalwade R. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Abstract Central venous catheter insertion by Seldinger's technique is a very common procedure nowadays. The technique though considered safe, is associated with potential dreaded complications. One such complication is intravascular loss of guidewire during insertion. We describe one unusual case of two chronically lost guidewires in venous and arterial system with successful retrieval by innovative interventional techniques. Keywords: Lost guidewire; Interventional cardiology; Interventionl AORTA-ARCH OF AORTA-LOOPING IN DESCENDING AORTA- radiology; Central venous catheter complications; Anaesthesiology; OPENING OF LT SCA (straight tip of guidewire). Snare We did routine blood evaluation, all were normal, venous and arterial Doppler and echo was done to rule out thrombus.
    [Show full text]
  • First Simulator for Seldinger Technique and Angiography Training
    This is a repository copy of ImaGiNe Seldinger: first simulator for Seldinger Technique and Angiography Training. White Rose Research Online URL for this paper: http://eprints.whiterose.ac.uk/79950/ Version: Accepted Version Article: Luboz, V, Zhang, Y, Johnson, S et al. (20 more authors) (2013) ImaGiNe Seldinger: first simulator for Seldinger Technique and Angiography Training. Computer Methods and Programs in Biomedicine, 111 (2). 419 - 434. ISSN 0169-2607 https://doi.org/10.1016/j.cmpb.2013.05.014 Reuse Unless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version - refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher’s website. Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing [email protected] including the URL of the record and the reason for the withdrawal request. [email protected] https://eprints.whiterose.ac.uk/ ImaGiNe Seldinger: first simulator for Seldinger technique and angiography training V. Luboz, Y. Zhang, S. Johnson, Y. Song, C. Kilkenny, C. Hunt, H. Woolnough, S. Guediri, J. Zhai, T. Odetoyinbo, P. Littler, A.
    [Show full text]
  • IVUS Imaging Catheters Reference Guide
    IVUS Imaging Catheters Reference Guide Peripheral Catheter Coronary Catheter Coronary Catheter Intracardiac Catheter OptiCross™ 18 OptiCross 6 OptiCross Ultra ICE™ Transducer 30 MHz 40 MHz 40 MHz 9 MHz Frequency Order Number H7493932800180 H7495181160 H749518110 M00499000 SFA, Popliteal, Typical Use Coronary Coronary Intracardiac Tibial, Renal Maximum Diameter 12 mm 6 mm 6 mm 50 mm Penetration Prep Location Proximal Proximal Proximal Distal Catheter 15 cm 15 cm 15 cm n/a Telescoping Length Sled Pullback Length 10 cm 10 cm 10 cm n/a Distance from 2.0 cm 2.0 cm 2.0 cm 1.0 cm Transducer to Tip Guidewire Lumen 1.6 cm 1.6 cm 1.6 cm n/a Length Guidewire ≤ 0.018" ≤ 0.014" ≤ 0.014" n/a Compatibility Sheath Compatibility 6 F 6 F 5 F 9 F (with max wire) Guide Catheter 6 F (ID ≥ 0.068") 6 F (ID ≥ 0.064") 5 F (ID ≥ 0.058") n/a Compatibility Crossing Profile 3.5 F 3.1 F 3.1 F n/a Imaging Window 2.9 F 2.9 F 2.6 F 9.0 F Profile Entry Profile 1.6 F 1.3 F 2.0 F 9.0 F Working Length 135 cm 135 cm 135 cm 110 cm OPTICROSS™ 18 CATHETER AND MDU5 PLUS BAG OPTICROSS 6 40 MHZ CORONARY IMAGING CATHETER CAUTION Federal law (USA) restricts this device to sale by or on the order of a physician. Rx only. Prior to use, please see the CAUTION: Federal law (USA) restricts this device to sale by or on the order of a physician.
    [Show full text]
  • PET/CT Lung Ventilation and Perfusion Scanning Using Galligas and Gallium-68-MAA Pierre-Yves Le Roux, MD, Phd,* Rodney J
    PET/CT Lung Ventilation and Perfusion Scanning using Galligas and Gallium-68-MAA Pierre-Yves Le Roux, MD, PhD,* Rodney J. Hicks, MBBS, FRACP, MD,†,z Shankar Siva, MBBS, FRANZCR, PhD,z,x and Michael S. Hofman, MBBS, FRACP, FAANMS, FICIS†,z Ventilation/Perfusion (V/Q) positron emission tomography computed tomography (PET/CT) is now possible by substituting Technetium-99m (99mTc) with Gallium-68 (68Ga), using the same carrier molecules as conventional V/Q imaging. Ventilation imaging can be performed with 68Ga-carbon nanoparticles using the same synthesis device as Technegas. Perfusion imaging can be performed with 68Ga-macroaggregated albumin. Similar physiological processes can therefore be evaluated by either V/Q SPECT/CT or PET/CT. However, V/Q PET/CT is inherently a superior technology for image acquisition, with higher sensitivity, higher spatial and temporal resolution, and superior quantitative capability, allowing more accurate delineation and quantification of regional lung function. Additional advantages include reduced acquisition time, respiratory-gated acquisition, and a lower impact on human resources. V/Q PET imaging offers an opportunity to improve the accuracy and util- ity of V/Q imaging in various pulmonary conditions. For pulmonary embolism, V/Q PET/CT scan may improve the diagnostic performance of the test owing to a better characterization of the pattern of defects and allow an accurate quantification of the extent of vascular obstruction. Establishing an accurate functional map of the regional ventilation and perfu- sion in the lungs may be relevant in many other clinical situations, including preoperative assessment of the lung cancer patients, radiotherapy planning, or presurgical evaluation of patients undergoing lung volume reduction surgery.
    [Show full text]
  • Coding Billing
    Coding&Billing Quarterly FEBRUARY 2015 EDITOR ALAN L. PLUMMER, MD ATS RUC Advisor Letter from the Editor Welcome to the January 2015 edition of the ATS Coding ADVISORY BOARD MEMBERS: and Billing Quarterly. The New Year will bring a number of KATINA NICOLACAKIS, MD important changes to medicine for practitioners of pulmonary, Chair, ATS Clinical Practice Committee ATS Alternate RUC Advisor critical care and sleep medicine. Below are some issues that ATS STEPHEN P. HOFFMANN, MD members and their staff need to be aware of and prepared for: Member, ATS Clinical Practice Committee ATS CPT Advisor ICD-10 Transition – Barring another last minute intervention MICHAEL NELSON, MD by Congress (which is possible but very unlikely), 2015 will Member, ATS Clinical Practice Committee be the year of the ICD-10 transition. I hope providers and ATS Alternate CPT Advisor practices are well underway preparing for the transition. Over the past year, the STEVE G. PETERS, MD Member, ATS Clinical Practice Committee ATS Coding and Billing Quarterly has featured articles on the transition. The April 2015 edition will cover ICD-10 for pediatric pulmonary services. Lung Cancer Screening Coverage – Earlier this month, the Centers for Medicare In This Issue and Medicaid Services (CMS) released its final coverage policy for lung cancer Low Dose CT Lung Cancer screening. In this issue, Dr. Kovitz describes the final coverage policy, its impact Screening Coverage - Implications on Medicare and private coverage, as well as tips for coding services related to for the Practitioner, page 2 screening. 2015 Brings New Extracorporeal Membrane Oxygenation New ECMO codes – Also covered in this issue is the new and expanded family of (ECMO)/Extracorporeal Life codes for EMCO services.
    [Show full text]
  • Study of Common Artifacts of Myocardial Perfusion Scan in Patients with Chronic Renal Failure and Liver Cirrhosis in Nuclear Medicine Ward of Namazi Hospital in 2019
    MedDocs Publishers ISSN: 2637-885X Journal of Radiology and Medical Imaging Open Access | Research Article Study of Common Artifacts of Myocardial Perfusion Scan in Patients with Chronic Renal Failure and Liver Cirrhosis in Nuclear Medicine Ward of Namazi Hospital in 2019 Hossein Akbarialiabad1; Sepideh Hesami1; Seyed Alihossein Zahrayi1; Masoud Vafabin2; Farshid Gheisari3* 1Student Research Committee, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran 2Department of general surgery, Shiraz University of medical sciences, Shiraz medical school, Shiraz, Iran 3Nuclear Medicine Department, School of Medicine, Imam Hossein Square, Shiraz, Iran *Corresponding Author(s): Farshid Gheisari Abstract Nuclear Medicine Department, School of Medicine, Background and objective: Myocardial Perfusion Imag- Imam Hossein Square, Shiraz, Iran ing (MPI) is one of the successful techniques for the diagno- sis of cardiovascular disease in both developing and devel- Tel: +98 916 301 1224; Email: [email protected] oped countries. In this imaging technique, like other imaging techniques, there is the possibility of error and unintended side effects such as artifacts that can be associated with the Received: Jun 15, 2020 device, user, and patient factors. Our study aims to assess the prevalence of artifacts in myocardial perfusion scans in Accepted: Jul 17, 2020 patients with chronic renal failure and liver cirrhosis. Published Online: Jul 23, 2020 Methods: In a cross-sectional study in 2019, 90 male pa- Journal: Journal of Radiology and Medical Imaging tients aged 45-65 years, who were referred to the Nuclear Publisher: MedDocs Publishers LLC Medicine Department of Namazi Hospital, were divided Online edition: http://meddocsonline.org/ into three groups of 30.
    [Show full text]
  • Nuclear Imaging in Pulmonary Medicine
    Nuclear imaging in pulmonary medicine 14/1/11 • Nuclear medicine as a branch of medicine is relativ ely yongoung • Involves the administration of radiopharmaceuticals into the body and measuring the radioactive decay of these compunds by various instruments, whic h is then converted into digital images • Different from conventional radiology in that there is no external radiation which is passed through the body • Commonly used nuclear medicine techniques in ppyulmonary medicine include ventilation‐ perfusion scanning(V/Q scan) and positron emissision tomography – CT fusion(PET‐CT) PET‐CT • PET (positron emission tomography) is the fastest growing imaging technique worldwide • It was first started in the 1970s • PET‐CT fusion was put into clinical practice in 1998 • Images the uptake and distribution of radiolabelled glucose in the body • PET alone is a functional imaging technique while the addition of CT to it makes PET‐CT both a functional and structural imaging technique Basic ppprinciples PET is based on two principles: 1. The widesprea d dis tr ibu tion of 18 fluoro‐2‐ deoxy‐D‐glucose (FDG) which is a glucose analogue and is tktaken up in altlmost every cell in the body – Within the cell the FDG is phosphorylated and is trapped allowing it to be effectively measured by PET – FDG has a half life of 110 min 2. The radioactive decay of the positron rich fluoride Unstable isotopes(18 F) undergo radioactive nuclear decay Emission of positrons (positively charged particles with the same mass as electrons) Positrons travel through the surrounding tissues and are annihilated by collision with a corresponding electron LdLeads to creation of two 511 kVkeV phthotons trave lling in opposite directions; called as coincidence annihillation Thousands of these annihilations are measured by the PET scanner Scintillation detector absorbs photons and converts them into optical light; Photomultiplier tube converts this into digital signals RddRecorded on a computer • PET images obtained are fused with CT images • Rationale 1.
    [Show full text]
  • Utility of CT Perfusion Scanning in Patient Selection for Acute Stroke
    Neurosurg Focus 30 (6):E4, 2011 Utility of CT perfusion scanning in patient selection for acute stroke intervention: experience at University at Buffalo Neurosurgery–Millard Fillmore Gates Circle Hospital PETER T. KAN, M.D., M.P.H.,1,4 KENNETH V. SNYDER, M.D., PH.D.,1,4 PARHAM YAshAR, M.D.,1,4 ADNAN H. SIddIQUI, M.D., PH.D.,1–4 L. NElsON HOpkINS, M.D.,1–4 AND ELAD I. LEVY, M.D.1–4 Departments of 1Neurosurgery and 2Radiology, and 3Toshiba Stroke Research Center, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York; and 4Department of Neurosurgery, Millard Fillmore Gates Circle Hospital, Kaleida Health, Buffalo, New York Computed tomography perfusion scanning generates physiological flow parameters of the brain parenchyma, allowing differentiation of ischemic penumbra and core infarct. Perfusion maps, along with the National Institutes of Health Stroke Scale score, are used as the bases for endovascular stroke intervention at the authors’ institute, regardless of the time interval from stroke onset. With case examples, the authors illustrate their perfusion-based imaging guide- lines in patient selection for endovascular treatment in the setting of acute stroke. (DOI: 10.3171/2011.2.FOCUS1130) KEY WORDS • computed tomography perfusion • acute stroke • stroke intervention ESPITE advances in pharmacological and mechani- tionale is that by limiting recanalization to patients with cal thrombolytic therapy, acute ischemic stroke large areas of ischemic penumbra, neuronal function may treatment remains
    [Show full text]
  • Open Seldinger-Guided Peripheral Femoro-Femoral Cannulation
    Chen et al. Journal of Cardiothoracic Surgery (2021) 16:199 https://doi.org/10.1186/s13019-021-01584-x RESEARCH ARTICLE Open Access Open Seldinger-guided peripheral femoro- femoral cannulation technique for totally endoscopic cardiac surgery Yi Chen1,2, Liang-wan Chen1, Xiao-fu Dai1 and Xue-shan Huang1,2* Abstract Background: The cannulation technique used in totally endoscopic cardiac surgery has a significant impact on the overall prognosis of patients. However, there are no large cohort studies to discuss it. Here we report on our research of using open Seldinger-guided technique to establish femoro-femoral cardiopulmonary bypass during totally endoscopic cardiac surgery and evaluate its safety and efficacy. Methods: The institutional database from 2017 to 2020 was retrospectively reviewed to find cases in which totally endoscopic cardiac surgery was performed. We identified 214 consecutive patients who underwent totally endoscopic cardiac surgery with peripheral femoro-femoral cannulation. All patients underwent femoral artery cannulation. Of these, 201 were cannulated in the femoral vein and 13 were cannulated in the femoral vein combined with internal jugular cannulation. The technique involves surgically exposing the femoral vessel, setting up purse-string over the vessels and then inserting a guidewire into the femoral vessel without a vascular incision, followed by exchange of the guidewire with a cannula. Results: Surgery indications included mitral valve disease in 82.71% (177/214), atrial septal defect in 11.68% (25/214) and tricuspid regurgitation in the remaining 5.61% (12/214). Hospital survival was 98.60% (211/214). There were no cases of stroke and postoperative limb ischaemia.
    [Show full text]