3D Models Related Images

Right Posterior View of Cerebellopontine Angle

Surgical Correlation


Right posterior view of cerebellopontine angle. The trochlear nerve can be seen near the top of the image after having emerged from the dorsum of the midbrain. It is the smallest of the cranial nerves but has the longest intracranial course of these nerves. Also, it is the only cranial nerve that originates from the dorsal surface of the brain. Here, it is seen coursing near the superior cerebellar artery, a vessel that supplies the midbrain. The trigeminal nerve can be seen emerging from the lateral pons. Posterior and inferior to it is the superior petrosal vein, an important venous channel draining the anterior cerebellum and brainstem. It is formed by union of several veins, including the transverse pontine vein, vein of the middle cerebellar peduncle, vein of the cerebellopontine fissure, the pontine trigeminal vein, and anterior lateral marginal vein. The superior petrosal vein empties into the superior petrosal sinus. Caudal to this vein, the facial and vestibulocochlear nerves leave the pontomedullary junction toward the internal auditory meatus or canal and are accompanied by the anterior inferior cerebellar artery. This artery gives rise to the labyrinthine artery that enters this canal with the nerves. It supplies the entire inner ear. The subarcuate artery, usually a branch of the labyrinthine or anterior inferior cerebellar artery, courses toward the subarcuate fossa, a tiny opening superolateral to the internal auditory canal. Here, it enters the petrous bone supplying it and the bony labyrinth.  A portion of the posterior inferior cerebellar artery can be seen at the lower border of this image. (Image courtesy of AL Rhoton, Jr.)