MRI
There are multiple foci of restricted diffusion in the cerebellar vermis and both medial cerebellar hemispheres, with associated haemorrhage within the vermis. This causes moderate mass effect at the foramen of Magendie although there is no obstructive hydrocephalus.
There is no supratentorial restricted diffusion. There are several gliotic foci in the left centrum semiovale, left precentral gyrus and superior parietal lobule.
Near complete loss of flow signal is returned from the intracranial left internal carotid artery with flow reconstituting at the level of the posterior communicating artery. The terminal ICA, A1 and M1 segments return normal flow signal. No flow signal returns from the left PICA, the right PICA has a normal appearance.
IMPRESSION
Multiple foci of acute infarct with haemorrhagic transformation in the cerebellar vermis and medial cerebellar hemispheres (PICA territory). No obstructive hydrocephalus. Occlusion of the left internal carotid artery is again noted, with distal ICA flow reconstituting via the posterior communicating artery.