Legend Sagittal T1 and axial T2 weighted images demonstrate a small posterior fossa. There is pegging of the cerebellar tonsils inferiorly and uplifting of the tectal plate. The corpus callosum is hypoplastic. Myelination is about that of a newborn, and therefore is delayed.

Legend Axial T2 weighted images demonstrates crowding of the posterior fossa with the brain stem compressed anteriorly against the clivus. The corpus callosum is deficient. In the bottom right image there is interdigitation of the cerebral hemispheres posteriorly with absence of a normal appearing falx. Nodular gray matter heterotopias line the ventricles Key words: mri congenital developmental

Brain Diagnosis: Chiari 2 malformation