View of the left cerebellopontine angle. For orientation, the left lower corner of the image is rostral, the top border is caudal. The facial (CNVII) and vestibulocochlear (CNVIII) nerves exit the brainstem at the ventrolateral aspect of the pontomedullary junction and course laterally into the internal acoustic canal. Here, the facial nerve is located anterior and superior to the vestibulocochlear nerve. Also here, the anterior inferior cerebellar artery (AICA) is visible contacting the VII-VIII complex near the root exit zone. A loop of the anterior medullary segment of the posterior inferior cerebellar artery (PICA) is also present. (Image courtesy of AL Rhoton, Jr.)