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Cerebral venous outflow abnormalities, as transverse sinuses (TSs) stenosis,may underlie a picture of idiopathic intracranial hypertension (IIH). To identify the best non–invasive MR venography (MRV) technique for exploring the disturbance of flow of TSs in IIH patients, we compared threedimensional phase contrast (3–DPC) MRV images, acquired with different velocity encodings (15 and 40 cm/s) with two–dimensional time–of–flight (2D–TOF) MR images in 6 subjects with IIH and 12 age–matched normal controls. In both groups, we also measured flow velocity in TSs by using single slice 2D–CINE PC acquisitions. In all subjects with IIH, 3D-PC showed marked flow disturbance in the mid–lateral portion of both TSs when velocity encoding (VENC) was set to 15 cm/s while only a slightly irregular flow in TSs was detected when VENC was set to 40 cm/s or when 2D–TOF was used. By contrast, 3D–PC (VENC 15 and 40) and 2D–TOF techniques were comparable in detecting TS signal flow in normal controls. Measures of flow velocity, by using 2D-CINE PC, revealed a three–fold increase of velocity at the level of the flow disturbance in IIH patients compared to normal controls (p < 0.0001), suggesting a marked stenosis of mid–lateral portion of TSs in these patients. Setting the VENC to 15 cm/s on 3D–PC MRV may represent the best technical approach for visualizing disturbances of flow in TSs in subjects with symptoms suggestive of IIH. [ABSTRACT FROM AUTHOR]