Right vertebral artery dissection with acute cerebellar infarcts

Extensive acute infarcts involving the right cerebellum, sparing the middle cerebellar peduncle demonstrating restricted diffusion on DWI ( within SCA and PICA territory ). 

 Multifocal small acute infarcts involving the left cerebellum at inferomedial aspect, lateral aspect (AICA territory).

 Multifocal small acute embolic infarcts involving the pons, left posterolateral aspect of medulla.

 Mild extrinsic compression of fourth ventricle due to mass effect with mild obstructive hydrocephalus.

 Segmental loss of flow void along the course of left intracranial vertebral artery (left V4) likely suggestive of acute thrombosis.

Narrow left vertebral artery, basilar artery .

The right vertebral artery demonstrates segmental intraluminal low intensity curvilinear septum at mid cervical level ( approximately at C4-C6 level)- likely suggestive of segmental vertebral artery dissection

 Hypoplastic left vertebral artery with atheromatous changes at V3 segment.