DEVELOPMENTAL-CHANGES IN THE POSTERIOR CRANIAL FOSSA OF CHILDREN STUDIED BY CT

We reviewed 181 brain CT examinations, with no abnormal findings, to d etermine normative data for the posterior cranial fossa (PF) in childr en. The volume of the PF and the supratentorial cranial cavity (SC) wa s assessed by summing consecutive CT cross-sectional areas. Linear mea surements of the PF structures - cerebellum, vermis, brain stem and fo urth ventricle - were also performed. The PF grows rapidly during the first 3 years of life and thereafter a smaller increase in size is obs erved. All the PF structures showed a positive correlation with the PF volume. The PF volume increased in parallel with that of the SC and t he PF/SC volume ratio remained relatively constant during childhood, T he establishment of normative data for the volume of the PF and its co ntents may be of value in the CT study of diseases associated with mor phological alterations in the PF.