EVALUATION OF THE DIAGNOSTIC YIELD OF MRI IN THE DIAGNOSIS OF BRAIN TUMOUR

ABSTRACT

The aim of this research is to evaluate the diagnostic yield of MRI in the diagnosis of Brain tumour, at National Hospital, Garki Abuja. It is a retrospective study, which evaluated the diagnostic yield of MRI in the diagnosis of Brain tumour, the sensitivity, Specificity, and accuracy of the Imaging Procedure in the Management of Brain tumour. The study also showed the male and female distributions of brain tumour cases in the period of February 2009 and March, 2012. A total number of 116 records (52 males and 64 females) that met the inclusion criteria was retrieved and studied. The result showed that MRI has a high estimated diagnostic yield with a value of 103 (88.79%) of the total population. The population of females (n=64; 55.7%) with brain tumour is greater than male, (n=52; 44.83%) patients. It was discovered that there is a high incidence of brain tumour in the locality. It was also discovered that MRI is a very useful tool in detection and management of brain tumour and as such, the MRI Scan should be utilized more for patients with Brain tumour.
LIST OF TABLES

TABLE 1Age Distribution of Brain tumour cases ---33
TABLE 2Relative Distribution of Sex and Age of Brain tumour Cases --------34
TABLE 3MRI Findings in Patients with Brain tumour. --35
TABLE 4Relative Sex Distribution of the highest occurring findings in patients    with Brain tumour ---36
TABLE 5Diagnostic yield of MRI in Brain tumour ---37
TABLE 6Sensitivity, specificity and Accuracy of MRI in detection of Brain tumour. -----38
TABLE OF CONTENT
             
Title Page----------i
Approval -----------ii
Certification ----------iii
Dedication -----------iv
Acknowledgement ---------v
Abstract -----------vi
List of Tables----------vii
Table of Content ----------viii

CHAPTER ONE:INTRODUCTION
1.1 Background of the Study -------1
1.2 Statement of Problem --------2
1.3 Objectives of the Study  --------3
1.4 Significance of the Study -------3
1.5 Scope of the Study --------3
1.6 Literature Review --------4

CHAPTER TWO:THEORETICAL BACKGROUND
2.1 Magnetic Resonance Imaging -------14
2.2 Brief History MRI ---------14
2.3 Principle of MRI Scan --------15
2.4 Specialised MRI Procedures -------17
2.4.1 Magnetic Resonance Angiography ------17
2.4.2 Diffusion MRI ---------17
2.4.3 Functional MRI  ---------18
2.4.4 Interventional MRI --------19
2.4.5 Multinuclear Imaging --------19
2.5 Anatomy of the Brain --------20
2.5.1 Major parts of the Brain and their functions -----21
2.5.1.1 Cerebrum ---------21
2.5.1.2 Cerebellum---------22
2.5.1.3 Brain Stem ---------22
2.5.1.4 Hypothalamus ---------22
2.5.1.5 Cranial Nerves ---------22
2.6 Classification of Brain Tumours -------23
2.7 Signs and Symptoms of Brain Tumours -----24
2.8 Diagnosis----------26
2.9 Treatment ----------27
2.9.1 Surgery ----------28
2.9.2 Radiation Therapy --------29
2.9.3 Chemotherapy ---------29
2.9.4 Immunotherapy ---------30
2.9.5 Others ----------30

CHAPTER THREE:  RESEARCH METHODOLOGY
3.1 Research Design ---------31
3.2 Area of Study ---------31
3.3 Target Population ---------31
3.4 Selection Criteria ---------31
3.5 Sample Size  ----------31
3.6 Equipment ----------31
3.7 Procedure for Data Collection -------32
3.8 Method of Data Analysis --------32

CHAPTER FOUR: RESULTS
4.1 Presentation of Tables--------33

CHAPTER FIVE: DISCUSSION, CONCLUSION AND RECOMMENDATIONS
5.1 Discussion ----------39
5.2 Summary of Findings --------41
5.3 Conclusion ----------42
5.4 Recommendations --------42
5.5 Limitations of Study --------42
5.6 Area of Further Study --------42
References -----------43
Appendix

INTRODUCTION

Brain tumor is an intracranial neoplasm or an abnormal growth of cells within the brain1. It is one of the most devastating forms of human cancers. They cause considerable concern due to their relatively high morbidity, mortality and enormous cost of care especially in the developing world where the financial burden is carried by the poor patient and his or her relations. Brain tumours develop as a consequence of cellular genetic alterations that permit them to evade normal regulatory mechanism and destruction by the immune system. These alterations may have an inherited or acquired (chemical, physical or biological) cause. Over all, only a small proportion of brain tumours can be attributed to the effect of inherit predisposition2.The various implicated and suspected environmental factors include: ionizing  radiation, non-ionizing radiation, N – nitroso compounds, viral infections (JC virus, cytomegalovirus, human immunodeficiency virus, sv-40, varicella zoster, chicken pox) and head injury2,3,4,5
Different imaging modalities have been used in the diagnosis of patients with brain tumour. Skull radiography, computed tomography and magnetic Resonance imaging are all important tools in the diagnosis of brain tumour in patients. However, skull radiography and CT are less used due to the risks associated with these imaging modalities. Therefore, MRI is currently the imaging modality of choice in the diagnosis of patients with brain tumours.6 For the fact that the use of MRI in brain imaging is rapidly increasing because of its relevance in both research and clinical medicine, the scanner hardware and MRI sequences are also improving. Performing MRI at higher resolution and field strength and  with more sensitive sequences have led to the detection of subtle or small brain abnormalities that may not be detected with other related modalities like computed tomography (CT)7. MRI studies of the brain is considered a better imaging technique than CT for two reasons: Firstly, MRI has a much higher contrast resolution when compared with CT for clear demonstration of normal anatomical structures and associated pathologies of the brain. Unlike CT angiography, intravenous contrast injection is not required for MR angiography. This is advantageous in patients with impaired renal function, contrast allergy or no intravenous access. Secondly, MRI does not involve radiation exposure unlike CT where x-ray source is used to produce image by exposing the patient to about 2msv of radiation which is twenty times that of conventional chest x-ray. It implies therefore, that one non-contrast CT brain study is equivalent to the amount of background radiation one experiences in about 8 months8. However, the use of MRI is contraindicated in patients with pacemakers and other metallic devices.
Any brain tumour is inherently serious and life-threatening because of its invasive and infiltrative character in the limited space of the intracranial cavity. So, there is need to evaluate the diagnostic yield of MRI in the diagnosis of brain tumour. This necessitates this study which will evaluate the diagnostic yield of MRI in the diagnosis of brain tumor in the institution under study.