Cerebral Venous System

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Cerebral venous sinus thrombosis (CSVT) can be a difficult thing to diagnose

NON CONTRAST CT

The first thing you’re looking for on a non con CT is a DENSE VENOUS SINUS: I follow the track of the superior sagittal sinus posteriorly and at the vertex and also the transverse and sigmoid sinuses

Secondly think about venous infarction - suspect this if there is an infarct that doesn’t fit an arterial territory and also remember venous infarcts are commonly haemorrhagic

POST CONTRAST CT

Look for an ‘empty delta sign’: look at the superior sagittal sinus on the post contrast and look for a triangle of peripheral enhancement with absence centrally. On the non contrast this will correlate with increased density

In general you’re looking for a filling defect within the venous sinuses which correlates with increased density on non contrast CT - ‘arachnoid granulations’ aren’t significant but can also cause filling defects which will conversely be LOW density on the non contrast CT

MRI

MRI venography can be done without contrast (time of flight) or post contrast with the latter more sensitive. Some studies have suggested CT venography to be more sensitive than this