Computer-tomographical appearances of the Chiari malformations of the posterior fossa.

The computer-tomography appearances of the Chiari I-III malformations are reviewed. The study is based on a series of 35 cases of Chiari I malformation, 116 cases of Chiari II malformation, and one case of Chiari III malformation. In our experience, a reliable diagnosis of all three types of malformation is possible on computer tomography. However, nuclear magnetic resonance imaging does reveal more detail and may become more important in the diagnosis of malformations of the posterior fossa structures.