The Basal Vein of Rosenthal. A, Anterior-superior view of the superior surface of the temporal lobe, temporal horn, and basal vein. The striate (purple interrupted line) and anterior peduncular (light green interrupted line) segments of the basal vein are located along the anterior segment of the MTR (yellow bracket). The posterior peduncular (purple interrupted line) and proximal mesencephalic (blue interrupted line) segments of the basal vein are situated in the middle segment of the MTR (green bracket). The distal mesencephalic segment (yellow interrupted line) of the basal vein belongs to the posterior segment of the MTR (red bracket). This is the most common pattern of the basal vein, in which the striate, peduncular, and mesencephalic segments drain posteriorly into the vein of Galen. The deep MCV and anterior cerebral veins join to form the striate segment, which courses below the anterior perforated substance and empties, in turn, into the peduncular and mesencephalic segments. B, Anterior-superior view of another temporal lobe. The left striate and peduncular segments of the basal vein are hypoplastic. The pattern on the right side is more typical in that the striate, peduncular, and mesencephalic segments are in continuity and drain posteriorly into the vein of Galen. The basal vein on the left side has hypoplastic striate and peduncular segments in conjunction with a large preuncal vein that drains forward into the sphenoparietal sinus. C, The right temporal horn has been opened, and the ambient and crural cistern have been exposed by opening the choroidal fissure. A normal configuration of the basal vein is observed. The amygdalar vein drains separately from the inferior ventricular vein into the basal vein. The anterior longitudinal hippocampal vein empties into the basal vein anterior to the inferior ventricular vein. D, Lateral view of the right tentorial incisura. The temporal lobe has been removed to expose the basal vein. The anterior peduncular segment of the basal vein, also referred to as the anterior anastomotic segment, is hypoplastic. Failure of anastomosis between the striate and peduncular segments of the basal vein results in formation of a prominent preuncal vein that drains forward into the sphenoparietal sinus. (Images courtesy of AL Rhoton, Jr.)