MRI demonstrating a Chiari III malformation with cervico-occipital encephalocele

Midsagittal T2-weighted MRI of an occipital encephalocele showing a bony defect involving the inferior occiput, foramen magnum, and posterior elements of C1 and C2 with herniation of the cerebellum (A) and occipital lobe (B). Note hindbrain abnormalities characterized by Chiari III malformation.