Radiology Resident Case of the Week
Bao Nguyen, M.D.
Peer Review Status: Internally Peer Reviewed by Daniel
Crosby, M.D.
Imaging:
The unenhanced CT images show a tubular hyperdensity
in the posterior interhemispheric fissure associated with a
triangular hyperdensity with a central isodense region at the
torcular herophili. This was initially interpreted as subarachnoid
hemorrhage from a suspected ruptured aneurysm.
The subsequent arteriogram as expected showed no
evidence of an intracranial aneurysm, arteriovenous shunting,
vasospasm or hyperemic blush. However, there was significant delayed
venous filling and poor to no filling of the superior sagittal sinus.
Diagnosis:
Superior Sagittal Sinus (SSS) Thrombosis.
Follow-up Imaging:
After a course of anticoagulation, MRV was performed showing partial recannalization of the anterior and middle segments of the superior sagittal sinus, but a persistent lack of flow within the posterior segment.
Etiology/Epidemiology/Pathophysiology:
Although there is a wide variety of conditions which predispose
people to venous sinus thrombosis including infection, dehydration,
trauma, shock, hypercoagulability, pregnancy, oral contraceptive use,
vasculopathy and even local tumor invasion, the prevalence of this
malady is unknown.
Miscellaneous:
Because the symptomatology of dural sinus thrombosis is nonspecific,
imaging studies play a vital role in the diagnosis of this
potentially devastating disorder. On non-contrast enhanced head CT, a
cord sign or tubular hyperdensity may seen in the acute setting along
with cortical and subcortical hemorrhage due to venous stasis and
infarction. With contrast enhancement, a filling defect within the
lumen of the thrombosed dural sinus (empty delta sign) may also be
seen, along with enlargement of medullary veins and other collateral
venous channels.
Key References:
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