Normal pressure hydrocephalus

Moderately dilated supratentorial ventricular system, with average-sized fourth ventricle. The degree of dilatation is disproportionate to the degree of sulcal effacement. The mamillopontine distance measures 11 mm.

High T2 signals are noted around the ventricles, reflecting periventricular permeation. 

Narrow callosal angle measured on coronal images at the level of the posterior commissure.  Normal floor of the 3^rd ventricle.

Markedly widened Sylvian fissures.

Scattered white matter T2 hyperintensities mainly at the periventricular area and centrum semiovale, reflecting deep white matter ischemic changes.

• ultrathin 3D sagittal T2W shows patency of the cerebral aqueduct with visualized flow void jet through it
• estimated absolute stroke volume is around 46 microliters
• peak velocity is averaging 5.92 cm/sec

Coronal T2-weighted image reveals distended lateral ventricles and narrowed callosal angle. The Sylvian fissures are prominent and there is relative crowding of the gryi towards the vertex. These appearances are suggestive of Normal Pressure Hydrocephalus.

The hippocampal and temporal lobe volumes appear preserved which would be against Alzheimer disease. Huntington disease would be best assessed more anteriorly by looking for caudate head volume loss. 

Image annotations and comments: Associate Professor Frank Gaillard

Source: Normal Pressure Hydrocephalus in Neurodegenerative MRI Online Learning Pathway

The patient underwent VP shunt placement which is seen here entering the right posterior parietal region and draining the body of the left lateral ventricle.

Mild diffuse symmetrical ectasia of the supratentorial ventricular system; together with widening of the cortical sulci and Sylvian fissures, as well as prominence of the basal cisterns, reflecting residual mild dilatation of the ventricular system. 

Right frontoparietal hypodense extra-axial subdural collection effacing related cortical sulci, likely right frontoparietal subdural hygroma.