 Brain MRI:Restricted diffusion with matching ADC hypointensity is evident throughout the right hemispheric white matter, sparing portions of the right frontal lobe and anterior temporal lobe, however not involving gray matter of the basal ganglia or cortices. Hemispheric mass effect is associated with this including sulcal effacement, partial effacement of right lateral ventricle, and persistent (2 mm) right to left midline shift. Basilar cisterns remain patent. There is also diffuse right hemispheric leptomeningeal enhancement as well as dural thickening with what appears to be asymmetrically enlarged cortical vessels on the right suggesting an increase of flow. Myelination in the involved areas appears to be mildly disrupted with T1 technique, which is not evident on the T2 technique. The left hemisphere and posterior fossa structures are not involved.Redemonstrated are subdural hemorrhages overlying the right hemisphere as well as involving the falx and tentorium. As before, the right hemispheric subdural hematoma measures up to 6 mm in maximal depth.The cerebellar tonsils are in normal position. There are no masses. The pituitary gland is normal in size. There is no evidence for intracranial hemorrhage or acute cerebral, brainstem or cerebellar infarction. No diffusion-weighted abnormalities are identified. There are no extraaxial fluid collections or subdural hematomas. The paranasal sinuses and mastoid air cells are clear. Brain MRA: There is antegrade flow within the distal bilateral vertebral arteries, within the basilar artery, distal bilateral internal carotid arteries and carotid siphons and bilateral anterior, middle and posterior cerebral arteries. No arterial stenoses, occlusions or aneurysms are identified. No arteriovenous malformations are identified and there is no evidence for cerebral vasculitis. Neck MRA:There is no evidence for stenosis of the origin of the great vessels or of the bilateral vertebral arteries. There are no stenoses of the bilateral common, internal or external carotid arteries or of the bilateral carotid bifurcations. There is no evidence for vasculitis, fibromuscular dysplasia or dissection of the carotid or vertebral arterial systems within the neck. There are no vascular masses identified. Cervical spine MRI:Alignment is anatomic. There are no fractures or subluxations. The marrow signal is benign. The cervical and upper thoracic cord are normal in signal. The cervicomedullary junction is normal. The cerebellar tonsils are in normal position. The visualized paraspinal contents are unremarkable. There are no osseous dysplasias or stenoses.
Restricted diffusion with matching ADC hypointensity is evident throughout the right hemispheric white matter, sparing portions of the right frontal lobe and anterior temporal lobe, however not involving gray matter of the basal ganglia or cortices. Hemispheric mass effect is associated with this including sulcal effacement, partial effacement of right lateral ventricle, and persistent (2 mm) right to left midline shift. There is also diffuse right hemispheric leptomeningeal enhancement as well as dural thickening with what appears to be asymmetrically enlarged cortical vessels on the right suggesting an increase of flow. Myelination in the involved areas appears to be mildly disrupted with T1 technique. The left hemisphere and posterior fossa structures are not involved. This constellation of features, in the setting of normal MR angiograms of the head and neck, are most suggestive of an encephalitic process, which includes consideration of Rasmussen encephalitis. An arterial or venous occlusive etiology for the ischemia is felt to be unlikely.