Spectrum of neuroradiologic findings in children with Chiari II malformation

Sagittal T1-weighted MR image showing Chiari II malformation in a child with myelomeningocele. Features include: elongated brainstem extending into the cervical spinal canal (A); downward herniation of the cerebellar tonsils into cervical spinal canal (B); small fourth ventricle (C); aqueductal stenosis (D); tectal beaking (E); large massa intermedia (F); thin corpus callosum (G). Additional findings include abnormal gyri of the cerebral hemispheres, cerebellar dysplasia, and reduced volume of the posterior fossa.