Intracranial arterial system: Infratentorial arteries

The main trunks of the vertebro-basilar system and major cerebellar arteries are characterized by a high degree of variability, which has been the basis of much clinical confusion, whereas the internal vascular patterns of the brainstem are relatively constant [24]. With such characteristics in mind, we review microangiographic findings to identify the course and distribution of individual vessels. To see the vascular territories of individual vascular groups on the axial section of the brain, we refer to the diagrams of the cerebellar arteries from Amarenco's group [1] and the diagrams of the internal vascular supply of the brainstem from Tatu and associates [27] that are based on the detailed study of Duvernoy [2].