Anemia and cerebral ischemia. Shown here is magnetic resonance imaging of the brain during (A) and 7 months after (B) an acute anemic event in a patient with sickle cell anemia who had no focal neurologic signs corresponding to the brain lesion. A focus of restricted diffusion on diffusion-weighted imaging (A) indicates this is an acutely ischemic lesion. (B) Typical, T2-hyperintense, permanent silent cerebral infarct corresponding to the focus of the acute ischemia detected during the acute anemic event. The imaging was obtained for a screening clinical research study, not for clinical suspicion of stroke.