Dural venous thrombosis - A neglected finding on routine MRI sequences

Abstract

AbstractObjectives - To establish the role of routine MR sequences in diagnosis of dural venous sinus thrombosis. Materials and Methods - As dural venous sinus thrombosis has a non specific presentation, all the patients coming to our department for MRI head between March 2003 and May 2005 were looked for abnormal signal intensity within the dural sinuses. Twenty seven cases having loss of normal flow void within the major dural venous sinuses on routine sequences (FSE T2, SE T1 & FLAIR) were thought of having dural sinus thrombosis and so were further evaluated by MR venography. This study was carried out using 0.2 Tesla open magnet MR scanner (GE signa profile 4). Results - On routine MR sequences absence of dural sinus flow void was noted in twenty seven patients and suspicion of cerebral venous thrombosis was raised. The diagnosis of thrombosis was confirmed in twenty three patients by 2-D TOF MR venography and no thrombosis could be demonstrated in remaining four patients. Thirteen patients had multiple sinus involved whereas in ten patients only single sinus was involved. Out of these twenty three patients, apart from thrombosis, six had infarcts, three had mastoiditis and one of them had cerebellar abscess too. Hemorrhage was noted in five patients and the most interesting fact was that nine patients had normal brain parenchyma. Conclusion - Dural venous sinus thrombosis appears as loss of normal flow void on routine sequences especially on FSE T2W and FLAIR images. This fact may help us suspect DVT, and the finding can be confirmed by MR venography so that further management can be planned promptly.