Marked dilatation of the third and lateral ventricles with no evidence of periventricular transependymal oedema. The sagittal FIESTA sequence shows aqueduct stenosis (web or diaphragm).
Suprasellar and prepontine cyst of CSF signal on all sequences, displacing the third ventricle superiorly and optic chiasma and infundibulum anteriorly suggestive of an arachnoid cyst.
Moderate dilatation of the fourth ventricle communicating with infracerebellar cyst suggestive of Blake's pouch cyst.