Section Editor: Sandy Cheng-Yu Chen, M.D.
Taipei Medical University Hospital, Taipei, Taiwan
Figure Caption
Infarction of the cerebellum is relatively uncommon and accounts for approximately 1.5-2.3% of all cerebral infarctions. The posterior inferior cerebellar artery (PICA) is the largest branch of the vertebral artery, and it supplies the posteroinferior cerebellum, cerebellar tonsils, inferior portion of the vermis, and lower lateral part of the medulla. Occlusion of PICA or one of its branches or the vertebral artery leads to Wallenberg syndrome, also called lateral medullary syndrome, or PICA syndrome. The classic finding of cerebellar hemisphere involvement is in the inferior half, which appears hyperintense on T2WI (A, B) and shows restriction on DWI (C).