Dural Sinus Thrombosis: Long-Term Follow-Up by Magnetic Resonance Imaging

Abstract

Ten consecutive patients with superior sagittal (SSS, n = 7) and/or lateral (LS, n = 8, bilateral in 3) sinus thrombosis had control magnetic resonance imaging (MRI) performed 6 months after clinical onset. Abnormal signals were still noted in 4 out of 7 cases of SSS thrombosis and in 8 out of 11 cases of LS thrombosis. In only 3 patients follow-up MRI was entirely normal. Persistent abnormalities were usually more limited in length, involving only a part of the sinus. Compared with initial MRI, the signal from the affected sinus was often heterogeneous but predominantly isointense on T1-weighted images and hyperintense or isointense to brain parenchyma on T2-weighted images. A marked decrease in the size of LS was noted in 4 patients. One patient developed dural arteriovenous fistula. Six patients with persistent signal abnormalities at 6 months had control MRIs 6–12 months later. Little change was observed compared with MRI performed at 6 months. MRI results were consistent with angiographic data in the patients who had both examinations. The persistence of MRI abnormalities long after (up to 18 months) dural sinus thrombosis must be kept in mind to avoid erroneous diagnosis of acute dural sinus thrombosis.