MR reveals severe dilatation of lateral and third ventricles with periventricular transependymal oedema.
On midsagittal T2 DRIVE images, there is a horizontal web at the upper third of the aqueducts.
There is also effacement of cortical sulci in bilateral cerebral hemispheres due to diffuse brain oedema.
The fourth ventricle is normal in size. The tectal plate is unremarkable.