On sagittal images the cerebellar primary fissure is indistinct. The 4th ventricle is small and diamond shaped. Coronal images show an absence of a vermis with continuous cerebellar white matter tracts and cortex across the midline consistent with rhomboencephalosynapsis.
There is also posterior corpus callosum dysgenesis. Hydrocephalus is seen secondary to aqueductal stenosis with ventriculoperitoneal shunt tip seen in lateral ventricle.