Distinguishing primary hydrocephalus from atrophy resulting in compensatory enlargement of the CSF spaces as the cause of ventriculomegaly can be, at times, challenging in image interpretation.
Radiographic features
Features that favor hydrocephalus include:
- dilatation of the temporal horns
- lack of dilatation of parahippocampal fissures 4
- increased frontal horn radius
- acute ventricular angles
- periventricular interstitial edema from the transependymal flow
- intraventricular flow void from CSF movement on MRI
- widening of the third ventricular recesses: midsagittal plane
- upward displacement of corpus callosum 3: midsagittal plane
- depression of the posterior fornix: midsagittal plane
- decreased mamillopontine distance: midsagittal plane
- narrow callosal angle
- cingulate sulcus sign
