Brain and spine imaging artefacts on low-field magnetic resonance imaging: Spectrum of findings in a Nigerian Tertiary Hospital.

BACKGROUND: Low-field (LF) magnetic resonance imaging (MRI) is a technology that is widely used in resource-limited settings for clinical imaging. The images produced, even though of low resolution with noise and artefacts, provide valuable information and guidance for patient assessment and treatment. This study shows a spectrum of MRI artefacts that affect image quality during routine clinical neuroradiology practice using LF MRI in a Nigerian hospital and suggests ways to avoid them. MATERIALS AND METHODS: We retrospectively reviewed brain and spine MRI studies performed on a 0.36T MagSense 360 (Mindray, China) open MRI at our hospital over a 2-year period to identify image artefacts. About 90% of MRI studies performed at our facility during the study period were neuroimaging. The pattern and distribution of artefacts that featured during imaging were described and illustrative cases demonstrated highlighting their causes and ways to avoid or limit them. RESULTS: Of 936 brain and spine cases evaluated, 506 (54.1%) had artefacts with 369 (72.9%) seen in the brain. Truncation/Gibbs (37.6%) and motion (20.6%) were the most common artefacts in the series, seen most commonly in T2-weighted images. There was no significant difference in the proportion of artefacts between adults and children (P = 0.736). CONCLUSION: Artefacts are relatively common in neuroimaging with LF MRI and may potentially degrade image quality and interfere with accurate radiological reporting and diagnosis. Improving the recognition of LF MRI artefacts may assist imaging practitioners to avoid or limit their effect on image quality and interpretation.

Abdominal ultrasonography in HIV/AIDS patients in southwestern Nigeria.

BACKGROUND: Though the major target of the HIV-virus is the immune system, the frequency of abdominal disorders in HIV/AIDS patients has been reported to be second only to pulmonary disease. These abdominal manifestations may be on the increase as the use of antiretroviral therapy has increased life expectancy and improved quality of life. Ultrasonography is an easy to perform, non invasive, inexpensive and safe imaging technique that is invaluable in Africa where AIDS is most prevalent and where sophisticated diagnostic tools are not readily available. PURPOSE: To describe the findings and evaluate the clinical utility of abdominal ultrasonography in HIV/AIDS patients in Ibadan, Nigeria METHODS: A Prospective evaluation of the abdominal ultrasonography of 391 HIV-positive patients as well as 391 age and sex-matched HIV-negative patients were carried out at the University College Hospital, Ibadan. RESULTS: Of the 391 cases studied, 260 (66.5%) were females; the mean age was 38.02 years, (range 15-66 years). The disease was most prevalent in the 4th decade with an incidence of 40.4%. Compared with the HIV-negative individuals, the HIV+ group of patients had a significantly higher proportion of splenomegaly (13.5% vs. 7.7%; p < 0.01), lymphadenopathy (2.0% vs. 1.3%; p < 0.70), and renal abnormalities (8.4% vs. 3.8%; p < 0.02). There were no differences in hepatic and pancreatic abnormalities between the HIV+ and HIV- groups. There were significantly fewer gallstones in the HIV+ group (1.4% vs. 5.1%; p < 0.01). CONCLUSION: AIDS is a multi-systemic disease and its demographic and clinical pattern remains the same globally. Ultrasonography is optimally suited for its clinical management especially in Africa. Its accuracy and sensitivity may be much improved with clinico-pathologic correlation which may not be readily available in developing countries; further studies may provide this much needed diagnostic algorithms.

Intracranial Arterial Calcification in Black Africans with Acute Ischaemic Stroke.

BACKGROUND: Intracranial arterial calcification (IAC), a recognized marker of atherosclerosis on cranial computed tomography (CT), is an independent risk factor for ischaemic stroke. This study aimed to determine the prevalence, distribution, severity, and associations of IAC in adults with acute ischaemic stroke (AIS) at the University College Hospital, Ibadan, Nigeria. METHODS: Cranial CT images of 130 consecutive adults who presented with AIS were acquired on a 64-slice multi-detector Toshiba Aquilion scanner and evaluated for IAC in bone window on Vitrea® software using a semi-quantitative scoring method for extent, thickness, and length of calcifications in the large intracranial arteries. Associations of IAC with clinical and laboratory data were determined by statistical analysis at p < 0.05. RESULTS: There were 71 males (54.6%), and the mean age of all patients was 63.0 ± 13.2 years. Hypertension was the most common risk factor (83.1%). IAC was found in 121 patients (93.1%), predominantly in the carotid siphon (86.1%) followed by the intracranial vertebral arteries (9.3%), middle cerebral arteries (2.4%), basilar artery (1.2%), and the anterior cerebral arteries (1%). The burden of IAC ranged from mild (17.4%) to moderate (52.1%) to severe (30.6%). Age (p < 0.001), diastolic blood pressure (p = 0.037), and alcohol use (0.046) were significantly different among the patients with mild, moderate, and severe degrees of IAC. IAC was associated with age (p < 0.001), hypertension (p = 0.03), diabetes mellitus (p = 0.02), hyperlipidaemia (p = 0.04), and alcohol use (p < 0.001) but not with sex (p = 0.35). CONCLUSIONS: The burden of IAC is very high among native African patients with AIS and preferentially involves proximal inflow arteries. Therefore, the role of large vessel atherosclerosis in ischaemic stroke in native Africans should be explored in future multinational, multimodality studies.

Electroencephalography as a tool for evidence-based diagnosis and improved outcomes in children with epilepsy in a resource-poor setting.

INTRODUCTION: Electroencephalography (EEG) remains the most important investigative modality in the diagnostic evaluation of individuals with epilepsy. Children living with epilepsy in the developing world are faced with challenges of lack of access to appropriate diagnostic evaluation and a high risk of misdiagnosis and inappropriate therapy. We appraised EEG studies in a cohort of Nigerian children with epilepsy seen in a tertiary center in order to evaluate access to and the impact of EEG in the diagnostic evaluation of the cases. METHODS: Inter-ictal EEG was requested in all cases of pediatric epilepsy seen at the pediatric neurology clinic of the University College Hospital, Ibadan, Nigeria over a period of 18 months. Clinical diagnosis without EEG evaluation was compared with the final diagnosis post- EEG evaluation. RESULTS: A total of 329 EEGs were recorded in 329 children, aged 3 months to 16 years, median 61.0 months. Clinical evaluation pre-EEG classified 69.3% of the epilepsies as generalized. The a posteriori EEG evaluations showed a considerably higher proportion of localization-related epilepsies (33.6%). The final evaluation post EEG showed a 21% reduction in the proportion of cases labeled as generalized epilepsy and a 55% increase in cases of localization-related epilepsy(p<0.001). CONCLUSION: Here we show that there is a high risk of misdiagnosis and therefore the use of inappropriate therapies in children with epilepsy in the absence of EEG evaluation. The implications of our findings in the resource-poor country scenario are key for reducing the burden of care and cost of epilepsy treatment on both the caregivers and the already overloaded tertiary care services.

Comparative analysis of clinical and computed tomography features of basal skull fractures in head injury in southwestern Nigeria.

BACKGROUND: Basal skull fractures (BSF) in head injury may be missed clinically. Early detection ensures prompt treatment and prevention of complications We compared the clinical and Computed Tomography (CT) features of basal skull fractures in head injured patients in a southwestern Nigerian hospital. MATERIALS AND METHODS: Head injury patients who had cranial CT at a Southwestern Nigerian hospital were selected. CT images were acquired with a 64-slice Toshiba Aquillion CT scanner using a standard head protocol. The images were evaluated for evidence of skull fractures, and associated complications. The clinical data and CT findings were analyzed. RESULTS: One hundred and thirty patients were evaluated, including 103 (79.2%) males. Their ages ranged between 7 months and 81 years, mean 35 years (SD, 20.3). In 59 patients (45.4%, 59/130) BSF was detected on CT, while 71 (54.6%) had no evidence BSF. Forty-two (71.2%) of the 59 patients detected on CT had clinical suspicion of BSF (P < 0.001) while the remaining 17 (28.8%) were not clinically diagnosed. This equaled a sensitivity of 71.2% and, specificity of 90.1% for clinical determination of BSF in this study. There was no statistically significant difference between clinical and CT diagnosis (P > 0.05). The commonest observed clinical feature in patients with confirmed BSF was otorrhagia (45.8%) and the petrous temporal bone (45.8%) was the most commonly fractured bone. The BSF was caused most commonly by motor bike accidents in 53 (40.8%). The most common associated intracranial injuries were intracerebral haemorrhage (34.6%) and subdural (17.3%). CONCLUSION: It appears that neurosurgical evaluation is comparatively reliable in evaluating basal skull fractures in this study area even as they are consistently demonstrated by high resolution CT scanners. A clinical suspicion of BSF should warrant a closer detailed CT evaluation and reporting by radiologists.

Testicular tuberculosis presenting with metastatic intracranial tuberculomas only: a case report.

INTRODUCTION: Intracranial tuberculomas are a rare complication of tuberculosis occurring through hematogenous spread from an extracranial source, most often of pulmonary origin. Testicular tuberculosis with only intracranial spread is an even rarer finding and to the best of our knowledge, has not been reported in the literature. Clinical suspicion or recognition and prompt diagnosis are important because early treatment can prevent patient deterioration and lead to clinical improvement. CASE PRESENTATION: We present the case of a 51-year-old African man with testicular tuberculosis and multiple intracranial tuberculomas who was initially managed for testicular cancer with intracranial metastasis. He had undergone left radical orchidectomy, but subsequently developed hemiparesis and lost consciousness. Following histopathological confirmation of the postoperative sample as chronic granulomatous infection due to tuberculosis, he sustained significant clinical improvement with antituberculous therapy, recovered fully and was discharged at two weeks post-treatment. CONCLUSION: The clinical presentation of intracranial tuberculomas from an extracranial source is protean, and delayed diagnosis could have devastating consequences. The need to have a high index of suspicion is important, since neuroimaging features may not be pathognomonic.