Typical neuroimaging features of reversible cerebral vasoconstriction syndrome

(A) Head CT angiogram: sagittal, maximum-intensity projection image showing the classic "sausage on a string" appearance of both anterior cerebral arteries.
(B) Head CT: axial image showing subarachnoid hemorrhage overlying the right frontal lobe (arrow).
(C) Brain MRI: axial FLAIR image in the same patient showing the right frontal subarachnoid hemorrhage (arrow) as well as multiple dot-shaped hyperintensities (arrowhead) within the sulci of both hemispheres, suggesting the presence of dilated cortical surface arteries.
(D) Brain MRI: axial FLAIR image showing the posterior-predominant crescentic hyperintense signal in the cortical-subcortical regions (dashed arrow). Corresponding DWI and SWI (not shown) were normal. These findings suggest the presence of brain edema as described in the posterior reversible leukoencephalopathy syndrome.
(E) Brain MRI: axial DWI showing ischemic lesions (short arrows) in the bilateral "watershed" regions of the middle and posterior cerebral arteries.
(F) Head CT scan: axial image showing a left frontal parenchymal hemorrhage.