Importance of Unenhanced CT as a Screening Tool for Cerebral Venous Sinus Thrombosis

Background: Cerebral venous sinus thrombosis (CVST) is being diagnosed clinically and by noninvasive
imaging techniques early in its course for better prognosis and non-fatal outcomes. It hinders
proper drainage of deoxygenated blood from brain resulting in drastic hemodynamic changes which
can be fatal. It is more common in younger age group and women of child bearing age. Over the past
decade, epidemiology of CVST has significantly changed and is not a rare disorder anymore.
Methods: After obtaining institutional ethical review committee approval, retrospective data collection
of Magnetic resonance venogram (MRV) and CT Brain were performed between January 2007 and
December 2016. Hounsfield units were obtained from dural sinuses on CT only in cases that were
positive for sinus thrombosis on MRV.
Results: Total 554 positive venous sinuses in 350 patients as well as 2246 negative sinuses were
analysed in the same cohort. Mean age was 37.46 ± SD 15.4 years, range: 72 years, minimum 4, and
maximum 76 years. Only those cases were included who had MRV and non-contrast CT (NCT) within
24 hours of each other. The average Hounsfield units of vessels containing a thrombus was 60 ± 1.56
which was significantly higher than that of any other normal sinus in same patient 40 ± 0.28 (� <
0.05). Sensitivity, specificity, positive predictive value and negative predictive value were calculated
as 99.6%, 89.05%, 69.17% and 99.9% respectively.
Conclusion: Hounsfield unit can be used as a good screening tool for CVST. CVST is increasingly
common and highly treatable cause of stroke. The goal of imaging is to rapidly diagnose sinus
thrombosis and provide a ground for early treatment for this condition to produce optimal clinical
outcomes. Hounsfield unit is highly sensitive and specific for cerebral venous sinus thrombosis and
can be used as a good screening tool in patient suspected of CVST.