Cerebral Venous Sinus Thrombosis, a Nonenhanced CT Diagnosis?

Abstract

Purpose. Retrospectively evaluate the density of cerebral venous sinuses in nonenhanced head CTs (NCTs) and correlate these with the presence or absence of a cerebral venous sinus thrombus (CVST). Materials and Methods. Institutional review board approval was obtained and informed consent waived prior to commencing this retrospective study. Over a two-year period, all CT venograms (CTVs) performed at our institution were retrieved and the preceding/subsequent NCTs evaluated. Hounsfield Units (HUs) of thrombus when present as well as that of normal superior sagittal and sigmoid sinuses were measured. HU of thrombus was compared to that of normal vessels with and without standardisation to the average HU of the internal carotid arteries. Results. 299 CTVs were retrieved, 26 with a thrombus. Both raw and standardised HU measurements were significantly higher in CVST (p < 0.0001) compared to normal vessels. Both raw and standardised HUs are good predictors of CVST. A HU of ≥67 and a standardised measurement of ≥1.5 are associated with high probability of CVST on NCT. Conclusion. Cerebral venous sinus HU measurements may help improve sensitivity and specificity of NCT for venous sinus thrombosis and avoid potentially unnecessary follow-up examinations.

Radiological evaluation in patients with clinical suspicion of cerebral venous sinus thrombosis presenting with nontraumatic headache - a retrospective observational study with a validation cohort

“…The finding of hyperattenuation in a thrombosed sinus is in accordance with previously reported findings [11,12,[19][20][21]. In previously published material different cutoffs for HU have been proposed ranging from 62 to 70 [12,[19][20][21].…”

“…Patient age is one important consideration when deciding imaging strategy, since computed tomography (CT) exposes the patient to ionizing radiation [18]. Previous studies have reported on the diagnostic utility of nonenhanced head computed tomography (neCT) to suspect CVST due to high density in the sinuses [11,12,[19][20][21][22]. Despite previous reports suggesting the applicability of neCT to accurately identify acute CVST, other methods such as magnetic resonance imaging (MRI) or CT venography (CTV) are recommended to verify the diagnosis of CVST.…”

Plain CT vs MR venography in acute cerebral venous sinus thrombosis: Triumphant dark horse

“…The average HU of vessels containing a thrombus was 68 ± 1.56, which was significantly higher than that of normal vessels 52 ± 0.28. [ 15 ]…”

Factors affecting dural sinus density in non-contrast computed tomography of brain

“…Non-contrast computed tomography (NCCT) is widely used as the initial imaging modality of choice in neurological emergencies 2,10–13 . Increased attenuation of cerebral sinus venous structures is considered the only direct finding of acute CVST in the NCCT 11,14,15 . Increased sinus attenuation has the advantage of being objective and easily calculated, while being able to diagnose CVST in the acute stage, when treatment is most likely to be effective and associated with favorable outcome 13 .…”

“…Increased sinus attenuation has the advantage of being objective and easily calculated, while being able to diagnose CVST in the acute stage, when treatment is most likely to be effective and associated with favorable outcome 13 . The drawback of this sign is the influence of various factors like serum hematocrit level and dehydration on sinus attenuation that may lead to false positive results and inappropriate disposition 2,10,11,15 . The possibility of changing the intracranial vasculature computed tomography (CT) attenuation under the influence of variable factors is a long-held unestablished belief.…”