Radiological Findings By Magnetic Resonance (MRI) and Arteriography (MRA) Brain Imaging Compared to Neurological, Stroke and TCD Assessment in Children with Sickle Cell Anemia in Uganda

Background: Children with sickle cell anemia (SCA) are highly susceptible to stroke and other manifestations of pediatric cerebral vasculopathy. Detailed evaluations of children with SCA in sub-Saharan Africa are limited, especially magnetic resonance imaging and angiography (MRI/MRA). In a sample of Ugandan children receiving care at the Mulago Hospital sickle cell clinic in Kampala and were not on disease-modifying therapy, we examined the range of MR imaging findings, and how those findings correlated with standardized demographic, clinical, neurological and neurocognitive assessments. Methods: From within a larger sample of 265 participants with HbSS ages 1-12 years not taking disease-modifying therapy and enrolled in the BRAIN SAFE study, a sub-sample of 81 underwent non-contrast MRI/MRA on a 1.5 Telsa scanner. Participants also underwent 3 standardized assessments: neurocognitive testing by experienced testers using the Mullen Scales of Early Learning (for ages 1-4 years) or Kaufman Assessment Battery for Children, 2nd edition (for ages 5-12) (abnormal z-score of -2 or lower), stroke examination (PedsNIHSS) and transcranial Doppler ultrasound (TCD) using criteria for pediatric SCA. Participants undergoing MRI/MRA intentionally included 29 without any abnormal findings. MRI scans included T1- and T2- weighted images, T2 FLAIR and MRA three-dimensional time-of-flight technique. MR scans were interpreted by clinical and research methods, the latter per SWiTCH protocol (Helton, Blood 2014). Adjudication of differing reads was performed by a blinded third neuroradiologist. Results: A total of 81 children with SCA were examined by MRI/MRA. Mean age was 6.48 ± 2.75 years; 50.6% were male. Mean hemoglobin was 7.26±0.90 g/dl; 75% had hemoglobin Conclusion: High prevalence of pediatric cerebral vasculopathy was found on MR scanning. Despite clinical evidence suggesting abnormal neuropsychological testing or a prior stroke, not all of the children who had clinical evidence of neurological disorders had MRI evidence of a stroke. Additionally, a number with no evidence of stroke had infarct(s) on MRI, so-called "silent stroke." The strongest predictors of an abnormal MRI reading included having a detectable stroke or an abnormal TCD. MR imaging is a critical aspect of evaluating cerebral vasculopathy in this patient population, and will be an important measure when prospectively assessing impact in a treatment trial. Disclosures No relevant conflicts of interest to declare.