Prenatal magnetic resonance imaging of rhombencephalosynapsis and associated brain anomalies: report of 3 cases.

Rhombencephalosynapsis (RES) is a rare congenital abnormality characterized by vermian agenesis and fusion of the cerebellar hemispheres. In the 3 cases reported here, prenatal magnetic resonance imaging clearly depicted cerebellar features characteristic of RES, allowing a definite diagnosis.