 Brain MRI:There are innumerable, multifocal, T2 hyperintense abnormalities throughout the supratentorial and infratentorial brain. Within the supratentorial compartment these are primarily located in subcortical white matter locations, although lesions can be found within the corpus callosum and internal capsules. A lesion within the genu of the corpus callosum appears hemorrhagic, measuring 22 x 13 mm in axial dimension, accounting for the new right frontal horn compression. Within the posterior fossa, cerebellar hemispheres as well as the pons and pontomedullary junction are involved. To a lesser extent, several of these abnormal foci are associated with contrast enhancement. Susceptibility weighted image also demonstrates multifocal petechial hemorrhages throughout the involved areas.The basilar cisterns are maintained and there is no midline shift. The cerebellar tonsils are in normal position. The pituitary gland is normal in size. There is no evidence for acute cerebral, brainstem or cerebellar infarction. There are no extraaxial fluid collections or subdural hematomas.Brain MRV: There is normal venous flow demonstrated within the internal cerebral veins, vein of Galen, straight sinus, superior sagittal sinus and within the bilateral transverse and sigmoid sinuses. No dural venous sinus thromboses or occlusions are identified. Neck MRA:There are no stenoses of the bilateral common, internal or external carotid arteries or of the bilateral carotid bifurcations. There is no evidence for fibromuscular dysplasia or dissection of the carotid or vertebral arterial systems within the neck. There are no vascular masses identified.
1.There are multifocal T2 hyperintense abnormalities involving both supratentorial and infratentorial brain with associated enhancement and microhemorrhage as described in detail above. This constellation of imaging findings has been described in the literature for hemophagocytic lymphohistiocytosis. Cerebritis and/or lupus vasculitis is felt to be a less likely etiology for these lesions. PRES is not considered within the differential diagnosis.2.Negative MRV of the brain.3.Negative MRA of the neck.