53 year old female patient with sickle cell anemia with acute chest, obtunded. Question of CVA or encephalitis. There are scattered foci of restricted diffusion throughout both cerebral hemispheres consistent with perfusional acute ischemic infarcts. This is on a background of extensive chronic small vessel and lacunar ischemic disease which is in a watershed distribution. Patchy cortical and subcortical edema is seen involving the cerebral hemispheres and particularly the right temporal lobe. There has been interval progression in diffuse cerebellar edema, right greater than left, causing crowding of the brainstem and effacement of the 4th ventricle.There are innumerable punctate and ill-defined foci of susceptibility artifact throughout the cerebral hemispheres and particularly in the cerebellum. There is no abnormal intracranial enhancement. The supratentorial ventricles and basal cisterns are stable in size and configuration. There is no midline shift or herniation. The orbits, skull, paranasal sinuses, and scalp soft tissues are grossly unremarkable.
1. A few small acute perfusional ischemic infarcts are seen on a background of extensive watershed distribution chronic small vessel ischemic disease.2. Extensive susceptibility artifact is evident throughout the brain, and particularly the cerebellum, which could represent a component of chronic ischemic microhemorrhage or perhaps hemosiderosis from iron overload. Microhemorrhage secondary to a chronic coagulopathy would also be a reasonable consideration.3. The cerebellum appears diffusely edematous, the etiology of which is unclear. This could be ischemic in etiology, although there is no definite acute ischemia by diffusion-weighted imaging, or possibly related to toxicity from excessive hemosiderin deposition. Inflammatory and infectious disease can also produce a similar appearing cerebellitis type pattern of inflammation.4. Relatively asymmetric edema involving the right temporal lobe is of uncertain significance but coud be secondary to an infectious or inflammatory process, including viral infection.