Cerebral Venous Sinus Thrombosis on Unenhanced CT

Cerebral Venous Sinus Thrombosis on Unenhanced CT

Neurosurg Q 2015;25:154–160

The aim of the study was to investigate computed tomography (CT) signs of cerebral venous sinus thrombosis (CVST), so as to increase clinicians’ awareness of CVST and improve the sensitivity of the diagnosis.

Materials and Methods: We retrospectively analyzed all the CVST cases primary diagnosed by CT and confirmed further by magnetic resonance imaging (MRI) or other clinical methods within the past 4 years in our institution. In total, 11 cases including 6 male and 5 female patients with a mean age of 31.0 years were studied. All patients had emergency CT examination for complaints of headache. The initial CT examinations were performed within 7 days after the onset in 7 cases and over 7 days in the other 4 cases. Six cases had continuous follow-up CT examinations, twice in 4 and 3 times in 2. The analysis items focus on the density change by measuring the CT values of involved venous sinuses in different phases, as well as indirect signs including venous infarction and hemorrhage. As a comparison, we measured CT values of normal venous sinuses in 40 healthy people with age ranging from 20 to 60 years.

Results: Of the patients with CT examinations performed within a week after the onset, 6 cases displayed uniform high density in related venous sinuses with a mean value of 72 HU. One week later, the densities declined slightly or reached isodensity with a mean value of 58 HU. The follow-up CT demonstrated the density changes of sinuses with the extension of the course of CVST, from high density gradually attenuating into mixed density, and into isodensity at last. During 7 to 10 days after the onset in 3 cases, the involved sinuses showed central high density with peripheral isodensity. A change of involved sinuses from high-density to isodensity occurring in different sites was found in 1 case on follow-up CT. Cortical vein thrombosis with secondary hemorrhage in 2 cases and CVST with subarachnoid hemorrhage in 2 cases were revealed in our study.

Conclusions: On CT, the CVST presented as the attenuation of the sinuses from high to isodensity with its resolution course. In the first week, the involved sinuses mainly appear as high density, then in 7 to 10 days decrease to mixed density as central high density and peripheral isodensity, and gradually to uniform isodensity at last. The secondary infarction and hemorrhage are important indirect signs of CVST. Understanding the abnormal density change of venous sinuses and intracerebral indirect signs on CT could improve our diagnostic sensitivity for CVST.