Fig 1. Partially recanalized thrombosis of the left sigmoid sinus: 47-year-old man with 45-day history of headache (patient 3). Shown are an axial FSE T2-weighted image (T2WI) (A), an axial SE T1-weighted image (T1WI) (B), an axial SE T1WI after contrast (C), a source image from axially acquired TOF-MRV (D), an axial reformatted source image from CE-MRV (E), and a lateral projection volume rendered image from CE-MRV (F). The signal intensity of the thrombus was heterogeneous and primarily hyperintense relative to gray matter on T2WI (arrowhead, A), and isointense on T1WI (arrow, B). Flow voids were identified on parenchymal sequences (arrows in A–C) that correspond to recanalized channels on MRV techniques (arrows in D and E). Areas of thrombus were seen as regions of signal intensity void on the MRV images (arrowheads, D and E). Note that the channels are slightly larger and more ill-defined on CE-MRV (arrows, E). The thrombus enhances intensely after contrast administration (arrowhead, C). The recanalized channels are well seen on CE-MRV volume-rendered images (arrows, F). Filling defects consistent with thrombus are identified in among the recanalized channels (arrowheads, F).