High-signal venous sinuses on MR angiography: discrimination between reversal of venous flow and arteriovenous shunting using arterial spin labeling.

ASL is a simple and useful MR imaging sequence for differentiating between reversal of venous flow and CS DAVF. In the sigmoid and transverse sinus, ASL showed false-positives due to the reverse flow from the jugular vein, which may be a limitation of which radiologists should be aware.