Background: Time-resolved (TR) contrast-enhanced 3D MR angiography has recently received considerable attention for the workup of cerebrovascular diseases, foremost dural arteriovenous fistula and arteriovenous malformation, and potentially for the evaluation of dural sinus thrombosis. Thereby, the dynamic visualization of cerebral vessels is enabled similar to the principle of digital subtraction angiography. Yet, its voxel size is relatively large due to an inherent trade-off between the desired spatial and temporal resolutions. The goal of this study was to evaluate whether the limited spatial resolution of TR MR venography (MRV) is sufficient to visualize dural venous sinuses.
Methods: The prospective study included 20 patients without compromise of cerebral venous outflow. Two neuroradiologists independently graded the quality of visualization of 11 predefined dural venous sinuses on images of fast TR contrast-enhanced MRV (1.5 s/dataset; voxel size, 2 x 2 x 2.2 mm; acquisition time, 37.5 s) in comparison to time-of-flight (TOF) MRV (voxel size, 0.8 x 0.8 x 4 mm; acquisition time, 3 min 51 s) and steady-state contrast-enhanced 3D (VIBE) MRV (voxel size, 1.1 x 0.9 x 1.5 mm; acquisition time, 2 min 46 s).
Results: The torcular Herophili (p < 0.001), left (p < 0.001) and right (p < 0.01) transverse sinus, and right jugular bulb (p < 0.05) were visualized better at TR MRV than at TOF MRV. For visualization of the small inferior sagittal sinus, TR MRV was inferior to VIBE (p < 0.001) and TOF (p < 0.05) sequences. The visibility of all other dural sinuses was equal.
Conclusion: Despite the inferior spatial resolution, TR MRV depicted some large dural sinuses more clearly than TOF MRV. To overcome the visualization of smaller venous structures, TR MRV can be applied complementarily with high-resolution steady-state contrast-enhanced MRV.