Flow artifacts or anatomic variants of venous sinuses often make MR venography (MRV) interpretation difficult. The authors investigated cerebral MRV in 111 subjects with normal CSF pressure to identify the most common flow abnormalities of transverse sinuses (TS). Disturbance of venous outflow in one transverse sinus was commonly observed in 30% of subjects whereas flow abnormalities of both TS occurred in 2 of 111 individuals. Subjects with flow gaps in both TS should undergo lumbar puncture to exclude increased CSF pressure.