PATTERN OF FINDINGS IN MRI STUDIES OF THE CENTRAL NERVOUS SYSTEM IN PORT-HARCOURT URBAN

ABSTRACTMagnetic Resonance Imaging (MRI) has been hailed by many a finding as the imaging modality of choice in the diagnosis of both focal and non-focal neurological disorders. And for this reason, it has increasingly the first modality of recourse for almost any disorder of the CNS where it is available. However, prognosis of central nervous system diseases is poor in the third world countries such as Nigeria because it is not known/documented, the pattern of occurrence of findings in MRI of Central nervous System in the general population. Thus, this project set out to fill this knowledge gap by reviewing MRI investigations of the CNS at Port-Harcourt urban, using the University of Port-Harcourt Teaching Hospital as case study. The major objectives were to find out this pattern of findings in both symptomatic and asymptomatic subjects. A total of 150 patients within the three years under review met the criteria for inclusion, and therefore formed the population. It was found that 58.00% of the subjects were male, while 42.00% were female. 52.00% of the findings occurred in the brain, while (48.00%) occurred in the spinal cord. No healthy, asymptomatic subjects were scanned within this period, and therefore there were no findings from this group of subjects. The highest occurrence was found among patients of age group 31-40 years (19.02%), followed by the age group 51-60 years (16.57%). The highest occurring finding in the brain is Normal Scan (39.74%), while it is Spinal cord compression (26.61%) in the spinal cord. It was found that MRI findings in the CNS tend to increase with increasing patients’ weight, and an uncanny spike was observed in the frequency of findings in the month of October. Finally, the diagnostic yield of MRI in detecting all disorders of the CNS was calculated and found to be 72.67%, a lower figure than what had been found to be its yield when used to scan for individual disorders.

TABLE OF CONTENTS
Title Page----------i Approval Page---------ii Certification Page---------iii Dedication----------iv Acknowledgement---------v Table of Contents---------vi List of Tables and Charts--------viii Abstract----------ix
CHAPTER ONE:INTRODUCTION------1 1.1: Background of Study-----1 1.2: Statements of Problem-----2 1.3: General Objectives of Study----3 1.3.1: Specific Objectives of Study----3 1.4: Significance of Study-----3 1.5: Scope of Study------4 1.6: Basic Definition of Terms----4 1.6.1: Conceptual Definition of Terms----4 1.6.2: Operational Definition of Terms---5
CHAPTER TWO:LITERATURE REVIEW----7 2.1: Brain--------7 2.1.1: Incidental Findings-----7 2.1.2: Findings on Symptomatic Patients---9 2.1.3: Findings on Neoplasms-----9 2.2: Spinal Cord-------10 2.2.1: Incidental Findings-----10 2.2.2: Findings on Symptomatic Patients---11 2.2.3: Findings on Neoplasms-----13
CHAPTER THREE:RESEARCH METHODOLOGY--15 3.1: Research Design------15 3.2: Area of Study------15 3.3: Inclusion Criteria------15 3.4: Exclusion Criteria------15 3.5: Population-------16 3.6: Data Collection------16 3.7: Method of Data Analysis-----16
CHAPTER FOUR:PRESENTATION OF RESULTS--17
CHAPTER FIVE: DISCUSSION, SUMMARY AND RECOMMENDATIONS-------26 5.1: Discussion-------26 5.2: Summary of Findings-----29 5.3: Recommendations------30 5.4: Limitations of Study-----31 5.5: Areas of Further Study-----31 REFERENCES Appendix
LIST OF TABLES AND FIGURES
Table 1: Distribution of MRI Findings of Disorders in the Central Nervous System according to Age Table 2: Distribution of MRI Findings Central Nervous System according to sex Table 3: Distribution of Clinical History/Diagnostic Queries for Brain MRI Examinations Table 4: Distribution of Clinical History/Diagnostic Queries for Spinal Cord MRI Examinations Fig. i:Distribution of MRI Findings of all Disorders in the Brain and Spinal Cord of Symptomatic Patients Table 5: Distribution of MRI Findings of Brain Disorders Table 6: Distribution of MRI Findings of Spinal Cord Disorders  Fig ii:Distribution of MRI Findings of Disorders in the Central Nervous System according to Patients’ weight Fig iii: Frequency Distribution of Monthly MRI Findings of Disorders in the Spinal Cord Fig iv:Distribution of Findings of Disorders in Brain MRI Scans in the Month of October Fig v:Distribution of Findings of Disorders in Spinal Cord MRI Scans in the Month of October Table 7: Estimation of the Diagnostic Yield of MRI as a modality for investigation of the Central Nervous System Table 8: Diagnostic Yield of MRI for the Brain Table 9: Diagnostic Yield of MRI for the Spinal Cord
INTRODUCTION
The brain, cranial nerves, leptomeninges, spinal cord and eye make up the Central Nervous System (CNS) 1. Study of this part of the body as well as its associated disease conditions give rise to the medical field of Neurology. Diseases of the CNS can be congenital (16.4%) or acquired (83.6%) 1. Of the acquired cases, trauma (82%), including road traffic accident (RTA), forms the leading cause of neurological disorders1. Accurate diagnosis of neurological disorders requires highly specialised imaging equipment. Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) have proven to be most useful in neuro-imaging – radiographic investigation of the CNS2. However, MRI (with or without Gadolinium Contrast) is the preferred neuro-imaging modality. For instance, examination of metabolite peaks with MR Spectroscopy can differentiate between cerebral tumours, radiation tumours and cerebral abscess by identifying their different spectral profiles. Similarly, Emejulu et al3 refers to MRI as the “gold standard” for imaging soft tissue including the spinal cord. MRI can pin-point the location and extent of spinal cord trauma and demonstrate compressive lesions. The most distinguishing features that make for the diagnostic excellence of MRI include its knack for accurate delineation of soft tissues, and its specificity in differentiating between cerebral pathologies3. Others are its non-utilisation of x-rays, saving the patient risk of the possible effects of ionizing radiation. It is said that the radiation received from one non-contrast CT examination is equivalent to that received from 8 months of the natural backgroun4. Also, it has much higher spatial resolution. Studies show that MRI can reveal subtle lesions that were previously not seen on CT. It is much less invasive. MR angiography, unlike CT angiography, does not require percutaneous catheterization. Contrast media used for MRI have less propensity to cause allergic than reactions than conventional media4.  Many studies carried out mostly on Caucasian populations have reveal that incidental findings exist in MRI scans of healthy asymptomatic subjects. No such study has been carried out in the Negro population to know if findings would be the same. In the State of Port-Harcourt, South-South Nigeria, two MRI equipment that serve patients from all over the region is located at the University of Port-Harcourt Teaching Hospital (UPTH), and at Braithwaite Memorial Specialist Hospital (BMSH), both in Port-Harcourt. But there has not been any documented study on the study described above. Neither is there any on the pattern of findings from the investigations carried out with these equipment. This study aims to study the pattern of results of MR studies involving the CNS that have been done in the region so far to establish a reference point for health policy makers and other entrepreneurs who may want to establish new MRI facilities in the region.