Definition: The infratentorial compartment that contains the CEREBELLUM and BRAIN STEM. It is formed by the posterior third of the superior surface of the body of the sphenoid (SPHENOID BONE), by the occipital, the petrous, and mastoid portions of the TEMPORAL BONE, and the posterior inferior angle of the PARIETAL BONE.
NIM when merely locational; X ref CLIVUS: restrict to posterior cranial fossa; other clivus sites are indexed under specific cranial bone, as clivus ossis occipitalis goes under OCCIPITAL BONE; neopl: coord IM with SKULL BASE NEOPLASMS (IM)
