What is the "venous distension sign"?
The "venous distension sign" is well demonstrated in this case and is a marker of intracranial hypotension (see annotated image later in case). The sign refers to the presence of a convex inferior margin of the midportion of the dominant transverse sinus. This is distinct from the normal appearance of this segment which usually has a concave or straight lower margin.
VP shunt in situ. Slit-like lateral and 3rd ventricles. Distended dural venous sinuses with venous distension sign present on the sagittal T1 images. Thin pachymeningeal enhancement. Appearances are consistent with intracranial hypotension secondary to CSF overshunting.