Brain magnetic resonance imaging and angiography in children with sickle cell anemia in Uganda in a cross-sectional sample

ObjectiveChildren with sickle cell anemia (SCA) are highly susceptible to cerebrovascular injury. We performed brain magnetic resonance imaging and angiography (MRI-MRA) in Ugandan children with SCA to identify structural cerebrovascular abnormalities and examine their relationship to standardized clinical assessments.MethodsA sub-sample (n=81) was selected from a cross-sectional study of children attending SCA clinic, including 52 (64.2%) with and 29 (35.8%) without clinically detected abnormalities. Clinical evaluation included assessment for prior stroke, cognitive testing and cerebral arterial transcranial Doppler (TCD) flow velocity. MRI-MRA scans were interpreted by at least two neuroradiologists.ResultsMean age was 6.5±2.7 years, with 39 (48.1%) female. Mean hemoglobin was 7.3±0.9 g/dl. Overall, 13 (16.0%) were malnourished. Infarcts and/or stenosis were detected in 55 (67.9%) participants, with stenosis primarily in the anterior circulation. Infarcts were seen in those with normal 17/29 (58.6%) or abnormal 34/52 (65.4%) clinical testing (p=0.181). Neither abnormal MRI nor MRA was associated with age, sex, hemoglobin, or malnutrition. Abnormal MRA was highly associated with infarcts (p<0.0001). Participants with abnormal imaging had two-fold higher proportion of stroke on exam and/or impaired cognition. Stroke on exam was strongly associated with an imaging abnormality after adjusting for age, sex, malnutrition, and hemoglobin (OR 11.8, 95%CI 1.87-74.2).ConclusionOver half of these SCA children had cerebrovascular infarcts and/or arterial stenosis. Cerebrovascular disease was frequently undetectable by clinical assessments. While rarely available in under-resourced settings, MRI-MRA brain imaging is an important tool for defining SCA cerebrovascular disease and for assessing impact of clinical intervention trials