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MAGNETIC RESONANCE IMAGING EVALUATION OF LOW IN ADULT NIGERIANS AT THE NATIONAL HOSPITAL ABUJA, NIGERIA

BY

DR UMERAH Chinwe Kenechukwu (MBBS ENUGU)

DEPARTMENT OF RADIOLOGY, NATIONAL HOSPITAL, ABUJA

BEING

A DISSERTATION SUBMITTED TO THE NATIONAL POSTGRADUATE MEDICAL COLLEGE IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE AWARD OF THE FELLOWSHIP OF THE MEDICAL COLLEGE IN RADIOLOGY (FMCR).

NOVEMBER 2014

1

CERTIFICATION FROM THE PROJECT SUPERVISOR

This is to certify that the research project titled Magnetic Resonance Imaging

Evaluation of in Adult Nigerians at the National Hospital Abuja,

Nigeria, was carried out by Dr Umerah, C.K in the Department of Radiology NHA and that I supervised the work.

PROJECT SUPERVISOR

......

DR. AKANO, A. O [FMCR]

Chief Consultant Radiologist

Radiology department,

National Hospital Abuja,

Nigeria.

Date………………………..

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ATTESTATION

I confirm that this project work was carried out entirely by Dr Umerah C.K and duely supervised in the Radiology Department of the National Hospital Abuja.

------

Dr A.A. UMAR [FMCR]

Head of Department

Radiology department,

National hospital Abuja,

Nigeria.

DATE……………………………….

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DECLARATION

It is hereby affirmed that this work titled “MAGNETIC RESONANCE

IMAGING EVALUATION OF LOW BACK PAIN IN ADULT NIGERIANS

AT THE NATIONAL HOSPITAL ABUJA, NIGERIA” was carried out by me at the Department of Radiology, National Hospital Abuja. In addition, the work is original and has not been presented to any other college for any reason nor for publication elsewhere.

DR UMERAH, Chinwe Kenechukwu

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DEDICATION

In loving memory of my hero, my mentor, my dear father, late Prof Ben

C.Umerah, who remains my inspiration

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ACKNOWLEDGEMENT

Special thanks to Almighty God for His abundant blessings without Whom nothing is possible. Thank you to my lovely sisters, aunties and entire family who constantly support me, my supervisor Dr A.O Akano for his tutelage and guidance and all my teachers for their collective efforts and individual contributions.

I am grateful to all the staff of radiology department of National Hospital Abuja for their support.

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TABLE OF CONTENTS

1. Title page……………………………...... i

2. Certification ……………………………………...... ii

3. Attestation ………………………………………………...... iii

4. Declaration…………………………………………….………iv

5. Dedication ………………………………………………..…...v

6. Acknowledgements ………………………………….….……vi

7. Table of Contents………………………..…………..………..vii

8. Summary…………………………………………..……...... 2

9. Introduction……………………………...... 4

10. MRI Anatomy of the spine…...... 6

11. Justification …………………………...... 17

12. Objectives …………………...... 19

13. Literature review….…………….……….……………………20

14. Materials and methods…..………………………….………...37

15. Results ………………………………………………..……… 43

16. Discussion...……………………………………………………63

17. Conclusion………………………………...... 72

18. Recommendations ……………………….……………...... 73

19. References.………………………………….……….…………74

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20. Appendix I copy local HERC approval ...……….………...82

21. Appendix II consent form………………...... 83

22. Appendix III Study data sheet………………………….……..84

23. Appendix IV departmental MRI questionnaire…….…………86

The following terms and definitions were applied to this study:

1. Adult: individual aged 18 years and older.

2. Low back pain: Low back pain is usually defined as pain localized below

the line of the twelfth rib and above the inferior gluteal folds

3. Musculoskeletal disorder: Affecting the muscles and/or skeleton of the

spinal column eg lumbar .

4. Incidence: is the rate of new (or newly diagnosed) cases of the disease. It is

generally reported as the number of new cases occurring within a period of

time.

5. informally and misleadingly called a "slipped disc",

is a condition affecting the spine, in which a tear in the annulus fibrosus of

an allows the nucleus pulposus to bulge out. Tears are

almost always posterolateral in nature owing to the presence of the posterior

longitudinal ligament in the spinal canal.

6. TSE-Turbo Spin Echo

8

SE-Conventional spin echo

MSMA-Multi stack multi angle [used mainly for axial cuts]

TIRM-Turbo inversion recovery magnitude

FS-Fat Saturation

Summary

Introduction

Low Back Pain(LBP) is a common problem affecting both genders and most ages for which about one in four adults seek care within every six-month period. It results in considerable direct and indirect costs, which could be financial, workforce and social amongst others. Care-seeking behavior varies depending on cultural factors, the intensity of the pain and the extent of activity limitation and the presence of co-morbidity. Magnetic Resonance Imaging (MRI) has proven invaluable in the assessment, management and follow-up of LBP.

Aims and Objectives

This study aims at describing the patterns of low back pain and their MRI changes in the cohort study.

Methodology

This is a prospective, descriptive study carried out at the Department of Radiology of the National Hospital Abuja using open MRI 0.2T Magnetom Concerto

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(SIEMENS, Germany 2004) Syngo. Plain and contrast MRI images of the lumbar spine were acquired in both T1 and T2 weightings

Study duration was 2 years from January from 2012- December 2014.Informed consent was obtained from patients and/or their relatives.Patients’ demographic history was taken from their case notes, request cards and from the patients themselves. The MRI findings were cross tabulated with age group, gender, severity of pain and duration. The result was analyzed using the Statistical Package for Social Sciences.

Results

A total of four hundred patients were evaluated, there was a male preponderance

(54.5%). Their ages ranged from 21-81yearswith peak at the fifth decade. The incidence of degenerative disease was very high, 84% relative to other spinal abnormalities. Osteophytes, loss of disc signal and exit compression were the most common specific degenerative finding. Other MRI findings included vertebral body destruction, disc herniation, Modic changes of the vertebral bodies as well as narrowing of the spinal canal.

MRI continues to be the gold standard for imaging in the evaluation of low back pain .This study conclusively shows the high sensitivity of MRI in low back pain and is in accordance with data from other studies.

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There is need for an increase in availability and affordability of MRI for patients with low back pain to benefit from the sensitivity of this investigation.

INTRODUCTION

Back pain has affected humans throughout recorded history. The oldest surviving surgical text, the Edwin Smith papyrus from 1500 BC, includes a case of back strain. Two key ideas in the nineteenth century laid the foundations for the modern approach to back pain: That pain came from the spine; and that it was due to . There is however no evidence that back pain has changed1.

Low Back Pain is the most prevalent musculoskeletal condition and the most common cause of disability in developed nations2. A global review published in

2000 suggested that only one African study was available for inclusion 3. A recent publication in 2003, reports a much larger group of relevant African studies of which 67% were methodologically sound. This review indicates that there is little difference in the prevalence of Low Back Pain among Africans compared with that in developed countries4.

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The lifetime prevalence of Low Back Pain (at least one episode of Low Back Pain in a lifetime) in developed countries is reported to be up to 85%4. Low Back Pain results in significant levels of disability, producing significant restrictions in usual activity and participation, such as inability to work4.

Musculoskeletal complaints are the second most common reasons for consulting a doctor and constitute, in most countries, up to 10–20% of primary care consultations 5. In the Ontario Health Survey, musculoskeletal complaints were the reason for almost 20% of all health care utilization.2They were the most expensive disease category in the Swedish Cost of Illness Study, representing 22.6% of the total cost of illness; the greatest costs were indirect costs related to morbidity and disability6.

The total direct cost for use ofhealth services that results from musculoskeletal conditions was 0.7% of the gross national product in the Netherlands, 1.0% in

Canada, and 1.2% in the USA 7,8. The indirect costs of musculoskeletal conditions

(loss of productivityand wages) were much greater than the direct costs, corresponding to 2.4% and 1.3% of the gross national products of Canada and the

USA, respectively4.

The purpose of this study seeks to describe the MRI findings in patients with low back pain in an attempt to provide better understanding of the characteristics of

12 patients identified with a diagnosis of lowbackpain, and the estimation of healthcare utilization and costs.

MRI ANATOMY OF THE LUMBAR SPINE

The are the largest segments of the movable part of the and are characterized by the absence of the foramen transversarium within the transverse process, and by the absence of facets on the sides of the body. They are designated L1 to L5, starting at the top. This area of the spine is the source of much body motion and supports most of the body weight.

General Characteristics

Thefirst four lumbar vertebrae are typical while the fifth contains certain peculiarities, which are detailed below.

As with other vertebrae, each lumbar vertebra consists of a vertebral body and a vertebral arch. The vertebral arch, consisting of a pair of pedicles and a pair

13 of laminae,which enclose the vertebral foramen (opening) and supports spinous processes.

Vertebral body

The vertebral body is a thin ring of dense cortical bone shaped like an hourglass.

The vertebral body of each lumbar vertebra is large, wider from side to side than from front to back, and a little thicker in front than in back. It is thinner in the center with thicker ends and flattened or slightly concave above and below, concave behind and deeply constricted in front and at the sides.Outer cortical bone extends above and below the superior and inferior ends of the vertebrae to form rims. The superior and inferior endplates are contained within these rims of bone.

Pedicles

The pedicles are two short rounded processes that extend posteriorly from the lateral margin of the dorsal surface of the vertebral body. They are made of thick cortical bone, very strong, directed backward from the upper part of the vertebral body; consequently, the inferior vertebral notches are of considerable depth. The pedicles change in morphology from the upper lumbar to the lower lumbar. They increase in sagittal width from 9 mm to 18 mm at L5. They increase in angulations in the axial plane from 10 to 20 degrees by L5. The pedicle is sometimes used as a

14 portal of entrance into the vertebral body for fixation with pedicle screws or for placement of bone cement as with kyphoplasty or vertebroplasty.

Laminae

The laminae are broad, short, and strong. They form the posterior portion of the vertebral arch. In the upper lumbar region the laminae are ‘taller than wide’ but in the lower lumbar vertebrae the laminae are ‘wider than tall’. The laminae connect the spinous process to the pedicles. The laminae are two flattened plates of bone extending medially from the pedicles to form the posterior wall of the vertebral foramen. The Pars Interarticularis is a special region of the lamina between the superior and inferior articular processes. A fracture or congenital anomaly of the pars may result in a . The vertebral foramen within the arch is triangular, larger than in the thoracic vertebra, but smaller in the cervical region.

Spinous processes

The spinous process is thick, broad, and somewhat quadrilateral. It projects backward and ends in a rough, uneven border, thickest below where it is occasionally notched. The superior and inferior articular processes are well- defined, projecting respectively upward and downward from the junctions of pedicles and laminae. The facets on the superior processes are concave, and are

15 directed backward and medially while those on the inferior processes are convex, and are directed forward and laterally. The former are wider apart than the latter, since in the articulated column, the inferior articular processes are embraced by the superior processes of the subjacent vertebra.

Transverse Processes

The transverse processes are long and slender. They are horizontal in the upper three lumbar vertebrae and incline a little upward in the lower two. In the upper three vertebrae they arise from the junctions of the pedicles and laminae, but in the lower two they are set farther forward and spring from the pedicles and posterior parts of the vertebral bodies. They are situated in front of the articular processes instead of behind them as in the , and are homologous with the ribs. Of the three tubercles noticed in connection with the transverse processes of the lower thoracic vertebrae, the superior one is connected in the lumbar region with the back part of the superior articular process, and is named the mammillary process. The inferior is situated at the back part of the base of the transverse process, and is called the accessory process.

Intervertebral Disc

Intervertebral discs are found between two vertebrae. The discs are flat, round structures about a quarter to three quarters of an inch thick with tough outer rings

16 of tissue called the annulus fibrosis that contain a soft, white, jelly-like center called the nucleus pulposus. Flat, circular plates of connect to the vertebrae above and below each disc. Intervertebral discs separate the vertebrae, but they act as shock absorbers for the spine. They compress when weight is put on them and spring back when the weight is removed.Intervertebral discs make up about one-third of the length of the spine and constitute the largest organ in the body without its own blood supply. The discs receive their blood supply through movement as they soak up nutrients. The discs expand while at rest allowing them to soak up nutrient rich fluid. When this process is inhibited through repetitive movement, injury or , the discs become thinner and more prone to injury. This may be a cause of the gradual degeneration of the structure and function of the disc over time.

Facet Joints

Joints between the bones in our spine are what allow us to bend backward and forward and twist and turn. The facet joints are a particular joint between each vertebral body that helps with twisting motions and rotation of the spine. The facet joints are part of the posterior elements of each vertebra9. Each vertebra has facet joints that connect it with the vertebrae above and the vertebrae below in the

17 spinal column. The surfaces of the facet joints are covered with smooth cartilage that help these parts of the vertebral bodies glide smoothly on each other.

LigamentumFlavum

The ligamentumflavum is a strong ligament that connects the laminae of the vertebrae. The term "flavum" is used to describe the yellow appearance of this ligament in its natural state. The ligamentumflavum serves to protect the neural elements and the spinal cord and stabilize the spine so that excessive motion between the vertebral bodies does not occur. It is the strongest of the spinal ligaments and often has a thinner middle section. Together with the laminae, it forms the posterior wall of the spinal canal.

Spinal Canal

The spinal canal is the anatomic casing for the spinal cord. The bones and ligaments of the spinal column are aligned in such a way to create a canal that provides protection and support for the spinal cord. Several different membranes enclose, nourish and surround the spinal cord itself. The outermost layer is called the "dura mater". The dura is a very tough membrane that encloses the brain and spinal cord and prevents cerebrospinal fluid from leaking out from the central nervous system. The other membranes include the arachnoids and the pia mater.

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The pia mater is a vascular membrane that closely covers the spinal cord. The arachnoid mater is a delicate impermeable membrane that covers the spinal cord and that lies between the pia mater internally and the dura mater externally. The space between the dura and the spinal canal is called the "epidural space". This space is filled with tissue, vessels and large veins. The epidural space is important in the treatment of low-back pain, because it is into this space that medications such as anaesthetics and steroids are injected in order to alleviate pain and of the nerve roots. The arachnoid mater is separated from the pia mater by a wide space known as the subarachnoid space which is filled with cerebrospinal fluid.

Spinal Cord

The spinal cord is part of the central nervous system of the human body. It is a vital pathway that conducts electrical signals from the brain to the rest of the body through individual nerve fibers. The spinal cord is a very delicate structure that is derived from the ectodermal neural groove, which eventually closes to form a tube during fetal development. From this neural tube, the entire central nervous system, our brain and spinal cord, eventually develops. Up to the third month of fetal life, the spinal cord is about the same length as the canal. After the third month of development, the growth of the canal outpaces that of the cord. In an adult, the

19 lower end of the spinal cord usually ends at approximately the first lumbar vertebra

L1, where it divides into many individual nerve roots.

Disc Psoas muscle Spinal nerve root Spinal cord Facet joints Epidural fat

Spinous process

Figure 1: An axial T1 weighted MRI image of the lumbar spine at the level of the disc showing the disc material which is isointense,spinal cord, nerve roots divergent from the exit foramina, normal spinous process and facet joints.

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Spinal Cord

Cerebrospinal fluid

Vertebral Body L3

L4/5 Intervertebral disc

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Figure 2: A non contrast sagittal T2weighted MRI image of the lumbosacral spine showing the normal anatomy of the vertebral bodies, intervertebral disc and nerve roots.

Spinal cord

Cerebrospinal fluid

Intervertebral disc

Vertebral body

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Figure 3: A sagittal non-contrast T1weighted MRI image of the lumbosacral spine showing hypointense discs, the CSF which is also hypointense and the isointense spinal cord

Percularities of the first and fifth lumbar vertebrae

The first lumbar vertebra is at the same level as the anterior end of the ninth rib.

This is also called the important trans-pyloric plane, since the pylorus of the stomach is seen at this level.

The fifth lumbar vertebra is the largest, strongest and most inferior of the lumbar vertebrae. It bears more body weight than the other vertebral bones and therefore most susceptible to stress related . The fifth lumbar vertebra is by far the most common site of spondylosis and spondylolisthesis10.Some individuals have four lumbar vertebrae, while others have six. These are variants of the normal anatomy. Lumbar disorders that normally affect L5 will then affect L4 or L6 in these individuals9,10.

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JUSTIFICATION

A review of research publications on low back pain suggests that most research have been conducted in the developed world. Low back pain exists in epidemic proportions in the western world and is on the increase. Its cause is mostly non- specific. Not much is known about it in the developing world because the data is scanty.1

Racial, economic and social homogeneity is not a feature of Africa, a developing continent. It is logical, therefore, to argue that genetic diversity, and differences in social structure and economics between the developed and developing nations, may underlie reported differences in the prevalence of LBP 4. Other African- specific factors such as the HIV and AIDS epidemic, types of work tasks and poor

24 nutrition may also influence LBP prevalence among Africans. These factors, thus underscore the need for this study to establish the characteristics of LBP in Abuja,

Nigeria.

The rationale for advanced imaging is frequently to identify rare but high- consequence conditions, such as metastases or infection. However, in the primary care population, less than 1% of all LBP patients have these conditions.

Whereas plain x-ray can demonstrate the vertebral body heights, subluxation,

Schmorls nodes, osteophytes, disc spaces and height, MRI can further show, in addition to all these, disc cartilage including dehydration, degeneration, prolapsed, spinal cord stenosis, changes in the cord, caudaequina/nerve root compression, with excellent resolution.

All these features will definitely lead to appropriate and more confident diagnosis of the cause of LBP, which will lead to better and more definite patient management.

Hence, MRI is being recently adopted with the hope that it will improve our understanding of the physiopathology of the disease and assist in alleviating patients' pain and discomfort.

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OBJECTIVES

BROAD OBJECTIVES

To determine the characteristics of low back pain in adult Nigerians in Abuja including its etiology and MRI features.

SPECIFIC OBJECTIVES

1. To correlate the MRI findings of LBP to patients age, gender, clinical

presentation and where possible, predisposing factors.

2. To determine the sensitivity of MRI in the management of low back pain.

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LITERATURE REVIEW

Low back pain is usually defined as pain localized below the line of the twelfth rib and above the inferior gluteal folds 11, with or without leg pain; and it can be classified as “specific” (suspected pathological cause) or “non-specific” (about

90% of cases). Back pain is usually defined as acute if it lasts less than six weeks; sub acute when pain persists between six weeks and three months; and chronic when it lasts more than three months12. Frequent episodes are described as recurrent back pain. Most episodes of low back pain settle after a couple of weeks, but many have a recurrent course, with further acute episodes affecting 20–44% of patients within one year in the working population and lifetime recurrences of up to 85%13,14. Frequently, low back pain never fully resolves, and patients experience exacerbations of chronic low back pain4.

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According to a global review prior to 2000, there is a dearth of studies on low back pain carried out in Africa15. The author also reported a surge of low back pain studies after the year 2000. The report revealed little difference in the prevalence of LBP among Africans when compared with the prevalence of LBP in developed countries. The earliest publication in this review was written in 1990, which may indicate that LBP prevalence may be a relatively recent and emerging problem in

Africa16. An alternative hypothesis may be poor resource funding for chronic largely non-life threatening conditions like low back pain in the African continent when compared to more urgent health threats such as HIV/AIDS.

The most common population group studied was "workers". This finding is plausible given that there is a lack of legislation to support workers suffering from

LBP to ensure that they receive optimal rehabilitation and support. In contrast, in western societies, legislation to promote spinal health protects workers from lumbar spine injury or pain is in place and is monitored by government bodies17.

The lack of best practice rehabilitation methods for LBP which could prevent and disability is evident in the reports of the most common treatment methods reported in the African research to treat LBP. Despite the increasing scientific evidence from meta-analyses that active rehabilitation involving exercise is most effective in reducing disability and LBP recurrence18,19, the most common forms of management identified in this review were rest and analgesics. Well

28 designed prevalence studies into African LBP, coupled with intervention studies to test the effectiveness of high quality interventions should be undertaken to inform and transform labor legislation policies to ensure better support for workers suffering from LBP. The mean LBP point prevalence among the African adolescents was 12% and among the African adults 32% (range 10-59%). This finding negates any assumptions that LBP point prevalence is lower in the developing world than developed societies, as the range of LBP point prevalence among western societies is also reported to range between 12% and 33%15,20. This revelation supports the findings of the global burden of disease studies which predict that the greatest increases in LBP prevalence will be in developing nations22. Unfortunately, the data obtained from the studies included in this review is insufficient to ascertain the trend of LBP over more than 2 decades, as the earliest methodologically acceptable study reporting point prevalence was published in 199322. However, with over 80% of the included studies published after the year 2000, there will be the capacity in a few years time to predict African

LBP prevalence trends with some certainty.

The one-year LBP prevalence among Africans ranged from 14 -72%15. The one- year prevalence among western societies is reported to be between 20% - 62% 15.

Therefore it appears that the one-year prevalence estimated among Africans correlates with the one-year LBP prevalence in western societies. Similarly,

29 comparable findings were observed for lifetime prevalence estimates as African lifetime prevalence ranged from 28- 74%, whilst lifetime prevalence in Western societies ranged from 30- 80%20.

Advances in technology and the mechanization of industries in African countries may therefore be reflected in the high one-year and lifetime prevalence of LBP among Africans, reported in the past decade of research. However, there is insufficient data on rural populations as only three of the 18 methodological acceptable studies provided data exclusively on rural populations21,22,23. The prevalence reported in these studies is comparable to reported urban population prevalence, and may reflect that the considerable physical activities required for rural (farming) activities may be a risk factor for LBP21,22,23. The study by

Omokhodion illustrates that farming activities increase the odds of suffering LBP by four, compared with individuals not exposed to farming activities25. These findings related to one-year and lifetime prevalence, and further illustrates that

LBP among all Africans is of concern. Further research into the most effective strategies to manage and prevent LBP is warranted.

Back pain is very common, but its prevalence varies according to the definitions used and the population studied. A large study from the Netherlands reported an incidenceof 28.0 episodes per 1000 persons per year and for low back pain with an incidence of 11.6 per 1000persons per year. Low back pain affects men

30 a little more than women and is most frequent in the working population,with the highest incidence seen in those aged 25–64years25. New episodes are twice as common in people with a history of low back pain4. The global prevalence of general disability is highest in sub-Saharan Africa26.

The etiology of disability is multifactorial and varies between different parts of theworld26. The most apparent difference in disability between the developed and developing worlds is musculoskeletal disorders (in developed worlds)27. The difference in disability prevalence between the developed and developing worlds is one example of global differences in health. Musculoskeletal disorders [conditions affecting the muscles and/or skeleton of the spinal column] accounts for about

4.3% of disability life adjusted years (years living with disability) in the developed world, whilst it is reported as accounting for approximately1% in the developing world29. Pain and loss of function associated with musculoskeletal conditions primarily leads to disability2. The four major musculoskeletal conditions leading to disability include ,rheumatoid arthritis, osteoporosis and low back pain4.

The literature on the epidemiology of low back pain is accumulating, but for the most part, studies are restricted to high-income countries, therefore, little is known about the epidemiology of low back pain in the rest of the world30. In developed

31 countries such as the United States of America (USA) and Australia, low back pain prevalence ranges from 26.4% to 79.2%31,32.

Low back pain is the fifth most common reason for all physician visits in the

United States. Approximately 60- 80% of the US population experiences low back pain at some point during the lifespan, with approximately 14% experiencing serious low back pain (that is, pain persisting for more than 2 weeks)33 and nearly

8% reporting at least 1 episode of severe acute low back pain. Although back pain usually resolves spontaneously within 1 to 4 weeks, approximately 33% of individuals with low back pain continue to have persistent moderate-to-severe pain

1 year later, and approximately 20% of patients with back pain have pain that is severe enough to cause substantial limitations of normal activities33.

The little known about epidemiology of low back pain from the developing world has come from Nigeria, Southern China, Philippines and Kenya with a prevalence ranging from 0 - 16%1.

The cause of the vast majority of low back pain is unknown; current tests cannot identify a pathological cause for the pain in at least 85% of cases. That is, in 85% of cases, even when the most extensive testing is conducted, no apparent cause can be established34.

Only a small proportion (approximately 20%) of low back pain cases can be attributed with reasonable certainty to a pathologic or anatomical entity.

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Discogenic lower back pain (DLBP) is the most common type of chronic lower back pain (LBP), accounting for 39% of cases, compared to 30% of cases due to disc herniation, and even lower prevalence rates for other causes, such as zygapophysial joint pain ,1% of people presenting with back pain in primary care have a , 4% have compression fractures. Thus, diagnosing the cause of low back pain represents the biggest challenge for doctors in this field. Although

90% of episodes of acute low back pain settle within six weeks, up to 7% of patients develop chronic pain35.

The occurrence of low back pain is associated with age, physical fitness, smoking, excess body weight, and strength of the back and abdominal muscles.

Psychological factors associated with occurrence of back pain are anxiety, depression, emotional instability, and pain behaviour (e.g. exaggerated outward display of pain, guarding). Occupational factors, such as heavy work, lifting, bending, twisting, pulling, and pushing, clearly play a role, as do psychological workplace variables, such as job dissatisfaction. Psychosocial aspects of health and work in combination with economic aspects seem to have more impact on work loss than physical aspects of disability and physical requirements of the job.

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Figure 4: A sagittal non contrast T2weighted MRI image of the Lumbar spine showing the hypointense disc herniation between L4 and L5 vertebrae.

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Herniated disc

Figure 5: A non contrast axial T1weighted image of the lumbar spine demonstrating a moderate, eccentric left sided, hypointense herniation of the L5/S1 intervertebral disc. 1

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Chronic low back pain is a common problem in primary health care. It is frequently as a result of one or more of the following mechanisms;

(1) Non specific low back pain;

(2) Back pain associated with or ;

(3) Back pain referred from a nonspinal source;

(4) Back pain associated with another specific spinal cause (including infection, cancer, fracture, inflammatory disorders, and syndrome).

When acute back pain is associated with neurologic symptoms, then an extensive work up is warranted for the causes like herniated intervertebral disc, spinal stenosis, and , which accounts for only 5% of acute back pain cases 1.

The general diagnostic approach to low back pain is to check for ‘redflags’ in the history and that suggest the presence of , infection or spondyloarthridites, and for neurological compromise that could indicate that surgery is required (cauda equina syndrome). In the absence of these features, imaging is of limited value36.

Red flags suggestive of a potentially serious condition:

Cancer or infection

1. History of cancer.

2. Unexplained weight loss.

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3. Immunosuppression.

4. Intravenous drug use.

5. History of urinary tract infection.

6. Fever.

7. Pain increases during rest.

Cauda equina syndrome

1. Bladder dysfunction

2. Saddle anesthesia

3. Leg weakness

Significant trauma relative to patients’ age

1. Fall from height

2. Motor vehicle accident

3. Heavy lifting in elderly patients with osteoporosis or possible

osteoporosis33.

The guidelines recommend certain imaging approaches for patients who are thought to be at risk of the following conditions:

Cancer: Magnetic resonance imaging (MRI) is recommended for patients with a history of cancer who have a new onset of low back pain; lumbosacral plain radiography is recommended for individuals with unexplained weight loss, failure

37 to improve after 1 month, or who are over the age of 50. Either plain radiography or MRI is recommended for individuals with more than 1 of these cancer risk factors.

Vertebral infection: MRI is recommended for the assessment of patients with suspected vertebral infection.

Cauda equina syndrome: MRI is recommended for patients with features suggestive of cauda equina syndrome, including urinary retention, motor deficits that encompass multiple levels of the spinal cord, fecal incontinence, or "saddle anesthesia" (loss of sensation in the and ).

Vertebral compression fracture: Lumbosacral plain radiography is recommended for individuals with risk factors for vertebral compression fractures (including older age, history of osteoporosis, or a history of steroid use).

Ankylosing : occurs in the younger age. Features include: morning stiffness which improves with exercise, alternating buttock pain, and awakening due to back pain during the second part of the night occurs in the patients.

Anteroposterior pelvis plain radiography is recommended for these patients.

Severe/progressive neurologic deficits: MRI is recommended for individuals with severe or progressive weakness or other deficits.

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Herniated disc: ACP/ASP guidelines do not recommend imaging studies for suspected herniated discs unless the pain has been present for at least 1 month. For pain lasting 1 month or longer, MRI is recommended for visualizing the spine.

Spinal stenosis is suggested by a pattern of radiating leg pain, and is more common among older patients. As with a herniated disc, imaging is generally recommended only when symptoms have persisted for at least 1 month.

The guidelines also recommend that clinicians should not perform routine imaging assessments on individuals with nonspecific low back pain during the first 4 weeks. In the absence of red flags, few patients with acute back pain have serious conditions that require immediate intervention, and most patients will improve with conservative management.33

MRI is the imaging modality of choice for evaluation of suspected lumbar disc herniation. Although MRI provides excellent anatomic detail, the relationship between pathoanatomy and clinical symptoms is controversial. It can be difficult to know which details of the anatomic picture are important, and what findings are more likely than others to manifest clinically.

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Several studies have shown that MRIs of asymptomatic patients have a high prevalence of bulges and protrusions in the lumbar spine, but extrusions were rarely observed33.

Radiographs of the spine are not usually necessary unless an underlying disorder, such as , , infection, or malignancy, is suspected.

Computed tomography shows the bony anatomy and also gives the best images of the detail of facet degeneration and spinal stenosis. Magnetic resonance imaging is used to examine soft tissue structures, such as the discs and nerve roots. Isotope bone scanning is indicated in specific situations, such as suspected sacroilitis or malignancy 37.

MRI does not require radiation exposure and provides better visualization of soft tissue and spinal canal, and thus preferred over CT. MRI produces superb delineation of soft tissue structures; excellent characterization of medullary bone, direct multiplanar imaging and no radiation exposure37. It gives more specific and complete information about the anatomy and pathology of the lumbar spine than any other available diagnostic tool. The most common source of lumbar pain is related to some form of spinal degeneration37. Degenerative processes may affect the disc or other supportive structures and may occur as acute, subacute or chronic problems. Imaging studies may be needed to assess the entire lumbar motion segment, including the intervertebral disc, facet joints and vertebral body end

40 plates. Signal changes of the vertebral end plates and marrow were described and classified by Modic into three grades as follows - Modic type 1 being hypointense on T1weighted and hyperintense on T2weighted and are shown to represent bone marrow edema and inflammation Modic type 2 changes are hyperintense on

T1weighted and isointense or hyperintense on T2 weighted images and are associated with conversion of normal red haemopoeitic bone marrow into yellow fatty as result of marrow ischemia. And Modic type 3 changes are hypointense on both T1W and T2W images and were thought to represent subchrondral bone sclerosis. The absence of Modic changes, a normal anatomic appearance, has often been designated Modic type 038. MRI may delineate pathoanatomic and chemical changes of a degenerating disc before disc herniation, because the signal intensity is related to state of hydration of the disc28. MRI is the best examination to non- invasively provide such information38,39. Disc degeneration may affect the chemical composition, ligament integrity and morphology of the disc 2. MRI is also capable of delineating small tears in the annular fibers26,39. When nuclear material is displaced, it is possible with MRI to differentiate between a contained, non contained or sequestered herniation.

Facet arthrosis may occur as a result of the altered functional status of a degenerated disc, because increased load is transferred to the facet joints. MRI may

41 reveal such changes as facet hypertrophy, osseous proliferation, cartilage narrowing, joint effusion and capsular hypertrophy.

Spinal stenosis is defined as a local, segmental or generalized narrowing of the central spinal canal or neural foramina by bone or soft tissue elements, an abnormality of canal will demand imaging that portrays spaces. Often associated with stenosis are hyperostotic ridges of the vertebral end plates, osseous proliferation of the facets and hypertrophy of the ligamentum flava. MRI may demonstrate the stenosis and define which structures cause the stenotic process 40.

MRI can accomplish that and also evaluate the true sagittal dimensions and cross- sectional area of the thecal sac.

MRI is the optimal modality to detect the presence of any inflammatory process involving disc, vertebral body or paravertebral soft tissue because of exquisite delineation of cancellous bone and soft tissues29. MRI is also the optimal examination to detect primary and metastatic in the spinal column, spinal cord or paravertebral soft tissues because it can noninvasively determine the exact position of the conus medullaris39, 40, 41.

Multiple reports document the accuracy of MRI in the evaluation of lumbar pathologic changes, but there has been a paucity of well-controlled studies that determine its efficacy and impact on patient outcome42,43,44,45.

42

MATERIALS AND METHODS

This is a descriptive, prospective study describing the MRI patterns of low back pain in adult Nigerians in Abuja.

The study was conducted in the Magnetic Resonance Imaging suite of the

Department of Radiology, National Hospital Abuja, Nigeria.

Patient selection

Four hundred eligible patients were selected on the basis of defined inclusion and exclusion criteria from all patients who were referred for Lumbar Magnetic

Resonance Imaging on account of low back pain within the study period (January

2012-December 2014) were evaluated.

SAMPLE SIZE DETERMINATION

The sample size was determined using Taylor’s formula: n=Z²pq/d² n = the desired sample size

Z = the standard normal deviate (1.96) at 5% level of significance. p = portion of target population (annual incidence of low back pain in

NHA) estimated to have a particular characteristics. q = 1.0 – p d = Degree of accuracy desired, set at 0.05

(1.96)2/0.05 (0.5)2(1-0.5)= 384.16

Total number of patients evaluated was 400.

43

Inclusion criteria

1. All patients aged 18 years and above who presented with low back

pain during the period of study.

2. All ethnicities were included.

3. All sexes were studied.

Exclusion criteria

1. Age less than 18 years.

2. All patients with any form of metallic implants ,cardiac pacemakers,

aneurysmal clips, gunshot pellets and bullets (In order to prevent metallic

objects from being attracted by the powerful magnet of the MR system

which could be harmful to the patient and also may distort images

produced).

3. Patients with history of previous reaction to contrast medium for scans that

require contrast.

4. Patients in renal failure or severe renal disease requiring contrast

(gadolinium is contraindicated in patients with renal failure).

44

Equipment /Technique and protocol

The MRI Machine used is the 0.2T Magnetom Concerto open magnet MRI scanner

(Siemens R 2004).

In all cases the spin echo [SE] and turbo spin echo [TSE] sequences were obtained with different recovery times[TR from 400-4500ms] and different echo times [TE from 19 to 141ms] and T1 of about 120ms.

A short TE and optimum TR were used to obtain good signal to noise ratio[SNR] and spatial resolution with reduction of the entire scan time.

Sagittal and axial slices will be used. Coronal scans were judged less informative owing to the curvature of the spine. Appropriate localizers will be obtained.

The protocol used was :T1W (Sagittal)(TR 412ms,TE 19ms,FOV

30x30cm,thickness 4.5mm,matrix 384x512).T2W (Sagittal)(TR3500ms,TE

125ms,FOV30cmx30cm,thickness 4mm,matrix (384x512),T2W axial (TR

3500,TE 141ms,FOV 21.7cmx24cm,thickness 5.0mm,matrix 384x512).Short Tau

Inversion Recovery(STIR)(Sagittal)TR2930,TE27, TI 120,FOV

11.8cmx20.0cm,thickness 5.0,matrix 228x512) and T1Wpost Gadolinum DTPA

(Diethylenetriaminepent- acetic acid)where necessary.

The body coil was employed for imaging of the lumbar spine.

45

LIMITATIONS OF THE STUDY

1. Some diseasepatterns of low back pain may be missed since not all

patients with low back pain can afford MRI.

2. Patients with any form of metallic implants including otolytic implants

were not evaluated due to the risks on MRI.

ETHICAL CONSIDERATIONS

Approval for this study has been obtained from the local institutional medical ethical committee and informed written consent was obtained from participants

The participants volunteered freely after being adequately informed on the need for thisstudy.

The participants’ confidentiality was maintained throughout the study.

The participants were also informed that they had the ability to withdraw at any stage of the study.

There was no harm done in any way or form to the participants.

IMAGING PROCEDURE

Each patient was interviewed using the departmental protocol/questionnaire

(appendix IV) to exclude any form of embedded metallic object inside the patient.

46

Appropriately signed informed consent form was obtained from each patient or any competent relation as the case may be. Each consenting patient was made to completely undress in a private room, removing all apparels and then dressed ina loose fitting gown provided in the department. A good venous line was secured for any patient who required contrast and was certified fit for contrast medium injection.

Technique and protocol setting

The spin echo (SE) pulse sequence technique with T1weighted (sagittal) and turbo

Spin Echo ( tSE )sequence with T2 weighted (sagittal and axial )baseline protocol were used for all patients. In addition, patients with suspected spinal masses had pre and post T1 weighted images.In cases where fat suppression was of diagnostic value, Short tau Inversion Recovery (STIR) sequence was added. The short echo time (TE) gave good signal to noise ratio and spatial resolution. The optimum repetition time(TR) used also minimized the examination time without compromising resolution.

Imaging the lumbar spine

Appropriate phased array coils were placed on the magnet table and the ports plugged and the patient placed supine, head first, with the lumbar spine centered over the selected coil. Accessories such as knee bolsters were used to flatten the lumbar curve as much as possible. Blankets were used to make the patient as

47 comfortable as possible. Appropriate sponges and straps were applied were necessary, for immobilization, stability and convenience. The alignment light was centered and patient instructed not to move during the scan. The sagittal and axial localizers were obtained for the subsequent full scan. Each scan took about thirty minutes. Following native studies, post contrast scans were performed in patients with where contrast could help aid diagnosis. This increased total scan time to about forty five minutes. Most of the patients tolerated the investigation, however a few complained of discomfort and claustrophobia.

48

RESULTS

Four hundred patients who satisfied the inclusion criteria were evaluated with

Magnetic Resonance Imaging during the study period.

Of all the patients,one hundred and eighty two (45.5%) of the patients were females and two hundred and eighteen (54.5%) were male, with a male to female ratio of 1.2:1.The ages ranged from 21 to 81years.The mean age was 50.96years.

The subjects studied were divided in into 7 age groups.

There was no significant statistic difference between the age and sex (p=0.219).

The age and sex distribution is shown on figure 6.

Most of the patients with low back pain were found in the age range of 41-60years.

Majority of the patients with abnormal MRI diagnosis were in the 5th to 6th decades of life.

Most of the patients (60.0%) were Christians, while Muslims accounted for 38.9% of subjects, the remaining 1.1% did not fall into either of these two religions(indigenous beliefs) as shown in figure 7.

About 60.7% of patients were educated up to tertiary level while 3.6% didn’t go to school at all. The remaining 35.7% stopped at primary and secondary school level

(Table 2).

Majority of the patients 86.4% that came for MRI evaluation were married, 9.1% were single, while 3.4% divorced and 1.1% widowed.

49

The distribution of clinical presentation of the patients is seen in Figure8with majority of patients (52.5%) having a history of sudden onset of pain, 11.2% of cases occurred following trauma, 15% were unspecified, 8.8% had the history of low back pain following a fall and 8.8% also occurred after heavy lifting, 3.8% were said to have the pain after waking up.

All the patients in the study group complained of low back pain with the duration of pain ranging from less than a week to more than one year.

Majority 47.1% of patients complained of severe pain as shown in table 3.

Pain duration was over a year in 55.7% of patients, while 27.3% complained of pain lasting between a month to one year,8% had theirduration of pain for less than a month, and 9.1% of patients, less than a week.

In all, fifty four (13.3%) of the patients with low back pain had normal MRI diagnosis while three hundred and forty six (86.6%) patients had abnormal diagnosis.

DISC CHANGES.

Decreased signal in the discs on T2 weighted images were seen in 76.4%,most of who were male. The most frequently affected disc level was at L4/5. Other changes seen in the disc included herniation which was seen in 77.1%,most common at

L4/5 level. Disc herniation was predominantly posterior and lateral (77.8%).

50

Exit nerve root compression was seen in 69.7%. Narrowing of the spinal canal occurred in 51.5% and was most common at L4/5 level.

VERTEBRAL BODY CHANGES

The most common cause of low back pain in the patients evaluated for this study was lumbar spondylosis [degenerative changes]which accounted for 84%. Majority of patients (62%) showed straightening of the lumbar curvature, 7.4% showed reversal of the curvature while 30.6% had preserved lumbar .Osteophytic spurs were found in 46.3%, decreased vertebral body height in 9% of cases, mostly at the L4/L5 level attributable to degenerative changes. However, reduction in height due to pathology was most common at L1vertebra (20%).

Modic changes were evaluated and majority (81.8%) had grade 0, grade 1 was seen in 11.3%, grade 2 in 1.5% and grade 3 in 5.5%(figure 9). The most commonly affected level for Modic change was L4/L5.

Destruction of vertebral bodies was a rare finding, occurring in

7.8%.Neoplastic/metastatic lesions were seen in 2.7%, Potts disease accounted for

0.9% and non-tuberculous infective lesions 3.3 %. Fracture was the least common cause of LBP and was seen in 0.9%.

In 9.9% of patients, mixed etiologies occurred (degenerative with either infectious or neoplastic causes).

51

Other findings included - effusion seen in 48.5% majorly at L4/5 level and spondylolisthesis in 39.4% most frequent at L5/S1 level.

52

Table 1: Showing the age of the patients with LBP and their frequencies

Ages(years) Frequency Percent

21 – 30 19 4.8

31 – 40 54 13.5

41 – 50 114 28.5

51 – 60 134 33.5

61 – 70 50 12.5

71 – 80 22 5.5

81 and above 7 1.8

Total 400 100.0

53

Age group 90

80

70

60

50 Male 40 Female 30

20

10

0 21 - 30 31 - 40 41 - 50 51 - 60 61 - 70 71 - 80 81 and above

Figure 6: Bar chart representing age group by gender of patients with LBP

54

Religion

Christian Muslim Others

1%

39%

60%

Figure 7: Pie chart representing the patients’ religion in patients with LBP.

55

Table 2: Level of education and percentage incidence

Level of education Valid percent

None 3.6

Primary 13.1

Secondary 22.6

Tertiary 60.7

100 Total

56

History of pain and the various causative factors 60.0 52.8 50.0

40.0

30.0

20.0 15.1 11.4 8.4 8.7 10.0 3.7 0.0 Fall Heavy lifting Sudden After waking Trauma Others onset up

Figure 8: Bar chart representing factors associated with pain.

57

Table 3 : Severity of pain and incidence in patients

Severity of pain Valid Percent Mild 11.8

Moderate 41.2

Severe 47.1

Total 100.0

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Table 4: Cross tabulation of occupation andMRI findings.

LS, Normal LS, ENRC LS, ENRC ENRC & LS, ENRC occupation Study & SS & METS INF & STM LS & ENRC LS & SS LS only Fracture Total Driver 0 4 0 0 0 0 0 0 0 4 0.0% 6.7% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 1.6% Force personel 0 0 0 0 0 0 0 4 0 4 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 10.0% 0.0% 1.6% Retired 0 20 4 4 0 8 4 0 0 40 0.0% 33.3% 50.0% 100.0% 0.0% 6.9% 50.0% 0.0% 0.0% 15.6% Housewife 4 4 0 0 0 20 0 4 0 32 50.0% 6.7% 0.0% 0.0% 0.0% 17.2% 0.0% 10.0% 0.0% 12.5% Trader/Business 0 8 0 0 0 8 0 0 0 16 0.0% 13.3% 0.0% 0.0% 0.0% 6.9% 0.0% 0.0% 0.0% 6.3% Civil servant 0 16 4 0 8 44 4 16 0 92 0.0% 26.7% 50.0% 0.0% 100.0% 37.9% 50.0% 40.0% 0.0% 35.9% Hospital worker 4 4 0 0 0 16 0 12 0 36 50.0% 6.7% 0.0% 0.0% 0.0% 13.8% 0.0% 30.0% 0.0% 14.1% Students 0 0 0 0 0 8 0 4 0 12 0.0% 0.0% 0.0% 0.0% 0.0% 6.9% 0.0% 10.0% 0.0% 4.7% Construction 0 4 0 0 0 4 0 0 0 8 worker 0.0% 6.7% 0.0% 0.0% 0.0% 3.4% 0.0% 0.0% 0.0% 3.1% Merchanics 0 0 0 0 0 4 0 0 0 4 0.0% 0.0% 0.0% 0.0% 0.0% 3.4% 0.0% 0.0% 0.0% 1.6% Artisans 0 0 0 0 0 4 0 0 4 8 0.0% 0.0% 0.0% 0.0% 0.0% 3.4% 0.0% 0.0% 100.0% 3.1% Total 8 60 8 4 8 116 8 40 4 256 100.0% 100.0% 100.0% 100.0% 100.0% 100.0% 100.0% 100.0% 100.0% 100.0% p=0.000

LS-lumbar spondylosis ENRC-exit nerve root compression SS-spinal stenosis METS- INF-infection/ STM-soft tissue masses

59

Table 5: Cross tabulation of occupation with the type of pain

Type of pain Occupation (scale of 1 - 10) Moderate Mild (1 - 5 ) (5-7) Severe(7-10) Total Driver 0 0 4 4 Force personnel 0 4 0 4 Retired 0 12 24 36 Housewife 0 12 20 32 Trader/Business 0 12 4 16 Civil servant 8 36 40 84 Hospital worker 4 16 16 36 Students 4 4 4 12 Construction 4 4 0 8 workers Mechanics 0 4 0 4 Artisans 0 0 4 4 Total 20 104 116 240

p=0.028

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Table 6: Cross tabulation of occupation and cause of pain

History Occupation of pain After Heavy Sudden waking Fall lifting onset up Trauma Others Total Driver 0 0 4 0 0 0 4 Force personnel 4 0 0 0 0 0 4 Retired 0 0 16 4 8 4 32 Housewife 4 0 20 0 4 4 32 Trader/Business 0 4 4 0 0 8 16 Civil servant 0 8 52 4 8 12 84 Hospital worker 4 8 20 0 0 4 36 Students 4 0 4 0 0 4 12 Construction 0 0 4 0 4 0 8 workers Mechanics 0 0 0 0 4 0 4 Artisans 0 0 4 0 0 0 4 Total 16 20 128 8 28 36 236 p=0.000

61

Modic changes

6 22

45

0 1 2 3

327

Figure 9: Pie chart representing Modic changes

62

Vertebral body height reduction 140 119 120 109 21 - 30 100 31 - 40 80 41 - 50 51 - 60 60 52 50 61 - 70 40 71 - 80 81 and above 20 15 16 14 8 3 2 5 3 4 0 Yes No

Figure 10: Bar chart representing vertebral body height reduction and age.

63

Disc level and signal change

MALE FEMALE

144

97 103 97 83 65 59 58

32 38

1 0

T1/L1 L1/L2 L2/L3 L3/L4 L4/L5 L5/S1

Figure 11: Bar chart demonstrating disc signal changes, disc level and gender

64

Posterior disc protrusion

Figure12: A sagittal T2 weighted image showing reduced signal of the disc at

L4/L5 level with posterior disc protrusion and indentation of the anterior theca.

65

Exit nerve root compression

Figure 13: An axial T2weighted MRI image of the lumbar spine of the same patient showing exit nerve root compression at L4/5 on the left side.

66

C

B

A

Figure 14: A sagittal T2 weighted image of the lumbosacral spine of another patient showing reversal of the lumbosacral curvature, osteophyte (A),type 2

Modic changes of the vertebral bodies(B) and dehydrated disc (C).

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Exit nerve roots

Figure 15: An axial T2weighted MRI image of the same patient showing bilateral exit nerve root compression of the lumbosacral spine at L2/L3 level.

68

Discussion

Studies of low back pain in the African continent were few prior to the year 2000, however of recent of recent there has been increased interest in this area particularly with the advent of MRI.

Magnetic Resonance Imaging demonstrates good anatomy of the lumbosacral spine. The various sequencies highlight the different aspects of the spine such as the vertebral bodies, intervertebral discs, spinal canal and neural elements. This allows for detailed evaluation and accurate diagnosis.

The peak age incidence of the cohort was consistent with previous report in literature. Low back pain is more common in the fourth to sixth decade and this has been attributed to the wear and tear that occurs with advancement in age.

However this study did not include individuals below the age of eighteen.

Earlier work by Nzeh and Komolafe48 on the lumbar spinal radiographs of patients symptomatic for low back pain showed a rise in the incidence of degenerative with a peak at seventh decade while this study shows a peak in the fifth decade which correlate with other more recent studies46,47. These observations may reflect a change in socio-demographic characteristic in this environment, over two decades. It may also reflect an earlier onset of symptomatic spinal degenerative disease due to lifestyle changes as predisposing factor29.

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Adeyinika47 and Omidiji’s47study on magnetic resonance imaging diagnoses in the lumbar spine of adults with low back pain showed a mean age of 53.27years, while that of Galukande1 et al showed a lower mean age of 43.83years, perhaps because most of Galukande’s patients were in the younger age group1. The mean age in this study was 50.1years; which is similar to those of Akano and Adeyinika et al 46,47.

The sex incidence is somewhat controversial: although the majority of studies including this study showed a male preponderance, others found low back pain to be common in females. This male preponderance is in concordance with some earlier studies such as Akano’s46 study which showed a male to female ratio of

2:146, Adeyinka47 et al which also showed a male to female ratio of 1.36:147.

The male preponderance, however, may be attributed to the increased level of physical / vigorous activities in which the male gender are believed to undergo leading to an increase in ‘wear and tear’ in the musculoskeletal system and thus predisposing them to an increase in the incidence of low back pain.These observations are supported by studies done by Miller at al27 where they concluded that the male discs degenerated more than female discs at most ages. And that the higher mechanical stress may be responsible for the earlier degeneration of male discs1,29

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The male to female ratio in this study agreed with that of Akano46and

Adeyinka47with the values of 1.22:1, 2:1 and 1.36:1 respectively.

This almost equivalent ratio of the sexes may indicate equality of male and female in the work place, ability to seek health care and level of education and enlightenment.

Most of the subjects (86.4%) in this study were married, which is the expected for the studied age group in this environment.

Majority of the patients (60%) were Christians, while 38.8% subjects were

Muslims, the remaining 1.2% were those with indigenous beliefs.

Although in Abuja, majority (50%) of the population are Muslims, 40% are

Christians and the remaining 10% are those with indigenous beliefs, 48 the slight

Christian predominance in this study, may be attributed to the way of life of

Muslims, in that the Muslim act of worship , involves frequent bowing down / prostrating during prayers known as sujud (sujud is an Arabic word meaning prostration to God in the direction of the Kaaba at Mecca which is usually done during the daily prayers. The position involves having the forehead, nose, both hands, knees and all touching the ground together),50hence a form of exercise, possibly reducing the incidence of low back pain in the Muslims populace.

71

Intercultural differences in perceiving or reporting back pain can be hypothesized as the most likely explanation of the markedly different prevalence rates of the disorder in the United Kingdom and East and West Germany51.

In describing the pain, up to 52.5% of patients in this study were unable to identify any causative or related factor and described the pain as sudden in onset; compared to the 19.2% of patients that associated their LBP with trauma or fall.

Upto 55.7% of the subjects complained of pain that had lasted over one year compared to the 9.1% that have had the pain for a week. This could be because most patients with a shorter duration of pain maybe experiencing acute low back pain, which usually resolves spontaneously with a short term use of medications, therefore not many of such patients will follow up on an MRI investigation33. As a result, a large proportion of patients undergoing MRI have long duration persistent low back pain.

Most people who experience activity limiting low back pain go on to have recurrent episodes.A wide range of factors are linked to both the onset and persistence of low back pain52.

Civil servants/office workers (35.9%) accounted for most of the occupation of the patients that were evaluated, while retirees accounted for 15.6%, hospital workers which included mostly nurses, doctors and hospital assistants (14.1%).

72

The reason for this could be attributed to the fact that, Abuja (FCT), where this study is being conducted, is the seat of government, and has a large government based work force, which are civil servants54 accounting for most of the participants in this study.Sustained sedentary occupation is a known risk factor for low back pain55.

Another factor could be that of affordability. Most of those that came for the MRI investigation were employed and could afford it. Conversely, the cost of the MRI investigation is seemingly high, in a developing country, where 2.46%54 are unemployed. Hence the unemployed with low back pain may not be able to afford the investigation and therefore will seek an alternative and cheaper way to be treated.

This present study showed a close relationship of physical loading occupations and low back pain that was statistically significant (with a p value of 0.0008). Most of the patients’ 65% in this occupational group were construction workers, who are involved in heavy lifting and probably developed low back pain due to wear and tear. This group of patients presented with a history of trauma prior to onset of pain.

There is frequent occurrence of loss of lumbar lordosisand was seen in 69.4% of cases. This however is a non specific finding and usually may be due to muscle spasm or probably poor posturing techniques.

73

Disc cartilage signal changes were seen in 76.4% of cases. Isolated reduction in height of the disc cartilages was seen in 0.9% of cases.

Studies have shown that the isolated loss of height at any one disc level is usually indicative of early degeneration.56

Several factors have been reported to cause disc degeneration. The decrease in the number and activity of disc cells depends on the mechanical loading, nutrient transport, life style, genetic factors and growth factors57.

Disc degeneration begins in early childhood as vessels within the disc space slowly regress. With increasing age, the metabolic strain to the intervertebral disc increases because of decreasing blood supply and decreasing diffusion. These metabolic changes lead to alterations in overall change in the disc space, decreasing the net inward flow of fluid and decreasing water content from 90% to

70%; this change ultimately leads to loss of disc height and expandability. Once the degenerative cascade begins, spinal mechanics are altered, and abnormal loading on adjacent levels may result in ligamentous strain causing pain58.

This study is on adults only, and the above scenario could explain the high percentage of subjects with disc signal changes from degenerative changes due to age.

A genetic predisposition to disc degeneration has been proven by studies on twins59. Previously, heavy physical loading was the main suspected risk factor for

74 disc degeneration. However, results of exposure-discordant monozygotic and classic twin studies suggest that physical loading specific to occupation and sport has a relatively minor role in disc degeneration, beyond that of upright postures and routine activities of daily living, showing that hereditary factors have a dominant role in disc degeneration59.

Osteophytic spurs were found in 46.3% of patients. Disc herniation was seen in

77.1% of cases. Posterior osteophytesand posterior disc herniation contribute to spinal and foraminal stenosis which all are known etiologies of low back pain60,61.

Progressive narrowing of the spinal canal can occur alone or in combination with disc herniations.This often occurs from acquired lumbar degenerative changes61.

In literature most cases of low back pain are due to various etiologies, such as degenerative changes, nerve root compression due to prolapsed disc, infective spinal pathologies such to tuberculosis and fractures.1

The major cause of low back pain in the subjects that participated in this study was degenerative process of ageing which is similar to findings in other similar studies1, 46, 47. Degenerative diseases of the spine [lumbar spondylosis] accounted for 84% of cases in this study showing the highest incidence of the diagnosed spinal abnormalities.

Other spinal abnormalities like metastasis and Potts disease showed very low incidence of 4.9% and 1.6% respectively.

75

This low incidence is possibly due to the fact that most of the patients that may have had other spinal abnormalities/lesions, for example, metastases to the lumbar spine, were not included in this study, since an MRI is not routinely requested for low back pain on account of clinical suspicion of metastasis to the spine.

Another plausible reason may be that the combination of clinical features, laboratory and radiographic findings may aid in diagnosing spinal abnormalities like metastasis or Potts disease without need to recourse to MRI especially when the cost implications and recourse challenges are put into perspective.

Metastasis has been noted as the most common tumor to affect the vertebral marrow, particularly in those over 40 years of age62. MR imaging has been advocated as a useful method for the evaluation of bone marrow diseases, including bone metastases11. This study agrees with the above because the only tumour found was metastases.

Spine infections are easily recognized on MRI and were seen in 6.9% of the patients in this study.

The 0.2 Tesla (low field) MRI machine used in this study was able to detect the cause of low back pain in the study subjects and the findings are comparable or similar to those in other studies where higher tesla equipmenthave been used.

76

It could therefore be concluded that the results obtained are accurate and that the equipment used is reliable and should be applied for future examinations.

77

CONCLUSION

Spinal degenerative disease changes were the commonest finding in this cohort

of patients studied for low back pain by MRI in Abuja.

Low back pain was more common in males than females and in the fifth decade

of life. Low back pain affected mostly those in the working class population.

MRI was used as a preferred imaging diagnostic tool due to its versatility and

accuracy in detecting spinal disorders.

The age of patients affected by low back pain is gradually decreasing if this

trend continues there will likely be a significant decrease in the productivity of

workforce. Therefore it is imperative that a sensitive means of detection be

made available and affordable.

MRI has proven to be a sensitive diagnostic tool for the evaluation of low back

pain irrespective of the field strength of the magnet used. It has been

demonstrated in this study that the protocols, technique and 0.2 Tesla strength

used for diagnosis were optimal and adequate.

78

RECOMMENDATION

1. The high cost of MRI examination limits the lower earning populace from taking advantage of the versatility of MRI for diagnosis of low back pain.

Attempts to reduce cost of the investigation should be made for easy access to less privileged. Indeed, MRI investigationfor LBP should be accessible through the

NHIS.

2. Availability: In as much as attempts are being made to get more MRI facilities available, they are still not easily available for those in the rural areas.

3. Service delivery: Maintenance of the machine requires regular power supply and trained personnel to ensure full working capacity; poor power supply is a national issue due to the poor power supply, which should be addressed to enable better service delivery to the populace. Exploration of the current solar supply should be considered.

4. Health education and awareness should be encouraged even among the literate to ensure appropriate investigation and diagnosis of low back pain.

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REFRENECES

1.Galukande M, Muwazi S, Mugisa D. Etiology of low back pain Mulago Hospital, Uganda. African Health Sciences 2005, 5(2):164-167

2.Yu S,Haughton VM, SetherLA.Criteria for classifying normal and degenerated lumbar intervertebral disks. Radiology 170 .1989; 523–526.

3.Grenier N, Greselle JF,Vital JM. Normal and disrupted lumbar longitudinal ligaments: correlative MR and anatomic study. Radiology 171 .1989; 197–205.

4. Louw QA, Morris LD, Grimmer-Somers K. The Prevalence of low back pain in Africa: a systematic review. BMC Musculoskeletal Disorders 2007;8:105.

5.Rasker JJ. Rheumatology in general practice. British Journal ofRheumatology.1995; 34:494-7.

6.Jacobson L, Lindgren B.What are the costs of illness?Stockholm:Socialstyrelsen (National Board of Health and Welfare).1996;

7.Coyte PC, Asche CV, Croxford R, Chan B.The economic cost of musculoskeletal disorders in Canada. Arthritis Care andResearch 1998; 11:315-25.

8.Callahan LF. The economic cost and social and psychological impact of musculoskeletal conditions: National Arthritis Data Work Groups. Arthritis Rheumatism.1995; 38:1351-62.

80

9. Bellenir K. Health Reference Series: Back and Disorder Sourcebook. Detroit, MI: Omnigraphics, Inc. 1997

10. Norman Eizenberg. General Anatomy:Principles and Applications .2008; 17.

11.Anderson JA. Epidemiological aspects of back pain. Journal of the Society of Occupational Medicine1986; 36:90-4.

12.Frymoyer JW. Back pain and sciatica. New England Journal of Medicine 1988; 318:291-300.

13. Felson DT. Does excess weight cause osteoarthritis and, if so, why? Annals of Rheumatic Disease.1996; 55:668-70.

14.Andersson GB. Epidemiological features of chronic low-back pain. Lancet 1999;354:581-5.

15.Walker B. The Prevalence of Low Back Pain: A systematic review of the literature from 1966 to 1998.Journal of Spinal Disorders 2000; 13(3):205-217.

16.Mulimba J.The problems of low back pain in Africa.East African Medical Journal.1990; 67:250-53.

17. Frank J, Sinclair S, Hogg-Johnson S. Preventing disability from work-related low back pain. Canadian Medical Association Journal 1998; 158(12):1625-31.

18. Hayden J,van Tulder M, Malmivaara A. Meta-analysis: Exercise Therapy for non-specific low back pain.Annals of Internal Medicine 2005; 142:765-75.

81

19.Machado L, de Souza M, Ferreira P, Ferreira M: The McKenzie method for low back pain.Spine2006, 31(9):E254-E262

20.Van Vuuren B, Zinzen E, van Heerden H. Psychosocial Factors related to lower back problems in a South African Manganese Industry.Journal of Occupational Rehabilitation 2005; 15(2):215-225

21. Omokhodion F, Umar U, Ogunnowo B. Prevalence of low back pain among staff in a rural population hospital in Nigeria.Occupational Medicine 2000; 50(2):107-110.

22. Omokhodion FO.Low back pain in a rural community in South West Nigeria West Far J Med2002, 21(2):87-90.

23.Fabunmi AA, Abe SO, OdunaiyaNA.Prevalence of low back pain among peasant farmers in a rural community in South West Nigeria. Afr J MedSci 2005, 34(3):259-262.

24.Omokhodion F.Lowback pain in an urban population in Southwest Nigeria Tropical Doctor 2004, 34:17-20.

25. Van den Velden J, De Bakker DH, Claessens AAMC, Schellevis FG. A national study of illness encountered in general practitioners' surgeries. Basic report: morbidity in general practice. Utrecht: NIVEL; 1991

26.Osti OL, Fraser RD. MRI and discography of annular tears and intervertebral disc degeneration.A prospective clinical comparison. J Bone Joint Surg 74B 1992: 431–435.

82

27. Miller JA, Schmatz C, Schultz AB. Lumbar disc degeneration: correlation with age, sex and spine level in 600 autopsy specimens. Spine 13.1988; 173–178.

28. Hickey DS, Aspden RM,HukinsDW. Analysis of magnetic resonance images from normal and degenerate lumbar intervertebral discs. Spine 1986 .11; 702–708.

29.Modic MT, MasarykT,Boumphrey F. Lumbar herniated disk disease and canal stenosis: Prospective evaluation by surface coil MR, CT and . Am J Roentgenol1986; 147; 757–765.

30. Lurie J, Doman D, David M.Magnetic Resonance Imaging interpretation in patients with symptomatic lumbar spine disc herniations: Comparison of Clinician and Radiologist Readings.Spine. 2009 April; 34(7), 1:701-705

31. Deyo R, Mirza S, Martin B. Back pain prevalence and visit rates: estimates from US National surveys, 2002.Spine 2006 , 31:2724-27.

32. Walker B, Muller R, Grant W. Low back pain in Australian adults. Prevalence and associated disability:Journal of Manipulative and Physiological Therapeutics 2004, 27:238-44.

33.Bowes MP:The Role of imaging in the evaluation of low back pain.eradioimaging.2010.

34.Refshauge KM, Maher CG:Low back pain investigations and prognosis; a review s Br J Sports Med 2006; 40; 494-498.

83

35.Cathy S.ABC of rheumatology of low back pain BMJ. 2004 May 8; 328(7448): 1119–1121.

36. Jon D. Lurie. What diagnostic tests are useful for low back pain? Best Practice & Research Clinical Rheumatology 2005 Vol. 19: 4, 557–575.

37.Richard J. Herzog, Alexander J. Ghanayem. Magnetic Resonance Imaging: Use in patients with low back pain or .Spine 2003; 3:65-105.

38. Rahme R, Moussa R. The Modic vertebral end plate and marrow changes:pathologic significance and relation to low back pain and segmental instability of the lumbar spine;ajnr May 2008 29:838-842.

39. Smith AS, Weinstein MA, MizushimaA. MR imaging characteristics of tuberculous spondylitis vs vertebral osteomyelitis. Am J Roentgenol 1989; 153:

399–405.

40.Kent DL, Haynor DR, Larson EB. Diagnosis of lumbar spine stenosis in adults: a meta-analysis of the accuracy of CT, MRI and myelography. Am J Roentgenol 1992;158: 1135–1144.

41.Avrahami ER. Tadmor, O. Dally H. Hadar.Early MR demonstration of spinal metastases in patients with normal radiographs and CT and radionuclide bone scans. J Comp Assist Tomogr 13 .1989; 598–602.

84

41.KattapuramSV,Khurana, JA. Scott, El-KhouryGY.Negativescintigraphy with positive magnetic resonance imaging in bone metastases.Skeletal Radiol19 1990; 113–116.

42.Sze G,Krol G,Zimmerman RG. Malignant extradural spinal tumors: MR imaging with gadolinium-DTPA. Radiology 167 (1988). 217–223.

43. Modic MT, Feiglin DH, Piraino DW. Vertebral osteomyelitis: assessment using MR. Radiology 157 .1985;157–166.

44.Wassenaar M,van Rijn RM, van Tulder MW, Verhagen AP, van der Windt et al. Magnetic Resonance Imaging for diagnostic lumbar spinal pathology in adult patients with low back pain or sciatic: a diagnostic review.Eur Spine J.2012 Feb;21(2):220-7.

45. Hancock MJ,Maher CG,Bogduk N.Systemic review of tests to identify the disc,SIJ or facet joint as source of low back pain.Eur SpineJ.Oct 2007; 16(10):1539-1550.

46. Akano, AO. Radiological Evaluation of Lumbosacral angle in patients with Low back pain in Ibadan Dissertation to National Post Graduate College, May1994.

47. Adeyinika AO, Omidiji OA. Magnetic Resonance Imaging Diagnoses in the lumbar spine of adults with low back pain in south west, Nigeria; West African journal of radiology; 2011 April;(18) :1.

85

48.Nze DA, Komolafe F. Radiological patterns of lumbar spinal degenerative changes in symptomatic patients. Rays (Roma) 1987:12n.3, 35-38

49. Abumere SI:The future population of the federal capital territory, Abuja.The Nigerian Journal of Economic and social studies.26 (3):287-313 2008

50.Mohammad,Mamdouh N.”Overview of Salat”.Salat: Islamic prayer from A-Z 2003;6-7.

51.Raspe H, Matthis C, Croft P, O'Neill T.Variation in back pain between countries: the Example of Britain and Germany. European Vertebral Osteoporosis Study Group Spine Phila . 1976. 2004; 29(9):1017.

52. Adams MA, Roughley PJ. What is intervertebral disc degeneration and what causes it? Spine 2006; 31:2151-21.

53.Taimela S,Kujala UM, SalminenJJ, Viljanen T. The prevalence of low back pain among children and adolescent: a national, cohort-based questionnaire survey in Finland.Spine,1997;22:1132-1136.

54. Employment,FCTmdgbaseline2010,www.mdgfctabuja.net/baseline10/ employment.aspx.

55..BurdorfA,Naaktgeboren, H C de Groot. Occupational risk factors for low back pain among sedentary workers.Journal of occupationalmedicine ; 35 (12):1213-20.

86

56.Sutton D, Stevens J,Kendrall B; Neuroradiology of the spine; Textbook of Radiology and Imaging; vol 2; 1643-71.

57. Yong-Soo Choi: Path physiology of Degenerative Disc Disease. Asian spine j June 2009 ;3(3):39-44.

58.Jill PG, Roberts S. Degeneration of intervertebral disc Arthritis Research and therapy 2003; 5:120-130.

59.Battié MC, Vide manT.Lumbar disc degeneration: epidemiology and genetics Bone Joint Surg Am. 2006; 88 Suppl 2:3.

60.Lamer TJ. Lumbar spine pain originating from vertebral osteophytesRegAnaesth Pain Med.1999 July-Aug; 24(4):347-52.

61. Genevay S, Atlas S..Best Prac Res ClinRheumatol. April 2010; 24 (2):253-265.

62. Algra PR. Detection of vertebral metastases:comparison between MR imaging and bone scintigraphy. Radiographics1991; 11:219-232.

87

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Appendix II CONSENT FORM

MAGNETIC RESONANCE IMAGING EVALUATION OF LOW BACK PAIN IN ADULT NIGERIANS AT THE NATIONAL HOSPITAL ABUJA.

I am Dr Umerah Chinwe, the principal investigator in the above study to be conducted at the National Hospital Abuja. The purpose of this study is to describe all the characteristics of Low back pain in adult Nigerians in Abuja including the etiology, prevalence and the usefulness of MRI in evaluating the patients.

The study involves assessing the MRI of patients referred for this purpose and will not involve the use of any ionizing radiation. Your participation in this study is voluntary and it is expected not to pose any burden except for the time spent in filling the attached form The immediate benefit to participants is prompt assessment of your MRI examination. The anticipated future benefit will help in the management of people with low back pain. All data will be treated as private and confidential, note that you are free to withdraw at any stage of the study.

If you have read and understood this document, or had it explained to you with the opportunity to ask questions, please sign or make a thumb print below Hospital number...... Signature...... Date......

In case of any enquiry please contact Dr UmerahChinwe Department of Radiology,NHA

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APPENDIX III

Data sheet 1. Study number 2. Identity number Patients initials 3. Age 4. Sex Male Female 5. Occupation

6 Level of education primary secondary Tertiary

7 Marital status married single divorced Widowed 8 Religion Christian Muslim Other 9 Weight[Kg] 10 Height[m] 11 BMI

12 Relevant past medical history

13 History of pain Fall After waking up Heavy lifting Trauma Sudden onset Others

14 Type of pain(scale of 1-10) Mild(1-5) Moderate(5-7) Severe(7-10)

15 Duration of pain 0-7days 1-3wks >4wks-12mths >1year

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MRI findings[to be filled by the doctor] Preserved Straightened angulated Exaggerated Others CURVATURE lordosis

VERTEBRAL BODY Normal decreased Shift{ant or post} others height

DISC CARTILAGE Normal Reduced prolapsed Signal thickness {ant/post} intensity

POSTERIOR Normal Signal changes others ELEMENTS

OTHERS

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APPENDIX IV NATIONAL HOSPITAL ABUJA DEPATMENT OF RADIOLOGY Patient’s Name…………………………Sex………. Weight…………………………………………. Date of birth…………………………Preparation…………Phone No………………………………… PLEASE FILL ACCURATELY YES NO Do you have a pacemaker or artificial heart valve Have EVER had metal fragments in youe eye(s) or worked with high speed metal machine tools? Have you EVER had a brain haemorrhage? Have you EVER had any surgery to your head or neck? Have you had any operation last year? Do you have any joint/limb replacements or metal implants ? Have any Sharpnel,war or bomb blast injuries? Have you sustained any gun injuries to any part of your body ? If yes which part? Could there be any metallic object on or within your body?If yes, where? Do you have afalse limb,calliper or brace? Have you ever cosmetic surgeries or tattoos? Are you epileptic? Have you ever had a fit Are you wearing a hearing aid? Are you wearing removeabke metal denture? Are you wearing patches(HRT, nicotine etc) Have you had MRI scan at this cntre before? If Yes put date (approx) Have you a followup consultation arranged? If Yes give date time and place For women of child bearing age;Could you be pregnant

Articles to be secured in lockers outside the scanning room. Hearing aids, keys, money, creditcards, watches, pagers,scissors, hairclips, jewelleries, etc. all articles are left entirely at owners risk. National Hospital Abuja cannot be held responsible for any loss or damage to any items.

I confirm that I have read the above and that it is correct to the best of my knowledge and believe.

Name & Signature …………………………………Date……………….

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(Patient/Guardian/others)

Witnessed by (Name & sign of Radiographer)…………………..Date……….

METALLIC OBJECTS  Remove all loose metal objects prior to scan.  Remove all credit cards  Be aware of objects on the trolley e.g oxygen cylinders

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