Sagittal Image shows a large posterior fossa cyst elevating the tentorium and sinus rectus (red arrow). The hypoplastic vermis is everted over the posterior fossa cyst (yellow arrow). The cerebellar hemispheres and brainstem are hypoplastic (green arrow). Thinned occipital squama is seen (blue arrow).
Axial image shows hydrocephalus, a large cerebrospinal fluid cyst in the posterior fossa and hypoplastic cerebellar hemispheres with a winged appearance (white arrowheads).