title: Posterior fossa malformations.
abstract: Understanding embryologic development of the cerebellum and the 4th ventricle is essential for understanding posterior fossa malformations. Posterior fossa malformations can be conveniently classified into those that have a large posterior fossa and those with normal or small posterior fossa. Disorders associated with a large posterior fossa include classic Dandy-Walker malformation, Blake's pouch cyst, mega cisterna magna, and posterior fossa arachnoid cyst. Disorders associated with normal or small posterior fossa include Dandy-Walker variant, Joubert syndrome, tecto-cerebellar dysraphia, rhombencephalosynapsis, the neocerebellar hypoplasias, and cerebellar atrophy. Neuro-imaging features should enable the imager to provide the referring physician a logical approach to these complex posterior fossa malformations.
authors: Department of Radiology, Division of Neuro-Radiology, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA. shekdar@email.chop.edu
authors: Karuna
authors: K
authors: Shekdar