Vertebrobasilar arterial system and major arteries with common variations of the cortical branches of the posterior cerebral artery (PCA). A, Lateral view. B, Anteroposterior view. Vertebral artery (VA) and basilar artery (BA) branches: anterior inferior cerebellar artery (AICA); posterior inferior cerebellar artery (PICA); superior cerebellar artery (SCA). PCA and its branches: calcarine artery (CalcA); parieto-occipital artery (ParOccipA); posterior choroidal artery (PChoA); posterior temporal artery (PTempA); posterior communicating artery (PCoA).