Fig 2.

Lateral venous phase DSA images illustrating the different variants of the basal vein of Rosenthal: BVR (yellow arrows), vein of Galen (red arrow), and straight sinus (dark blue arrow). A, Type A (normal continuous pattern). The BVR is continuous and drains mainly posteriorly into the vein of Galen. B, Type B (normal discontinuous pattern). Discontinuous dual drainage of the BVR anterior into the cavernous sinus via the uncal vein and posterior to the vein of Galen. The green dotted line and the 2 green arrows illustrate anterior and posterior drainage. C, Type C (primitive pattern). BVR drains into veins (the uncal, anterior pontomesencephalic, or lateral mesencephalic veins or the tentorial sinus) other than the vein of Galen. The anterior segment of the BVR (yellow arrow) drains into the lateral mesencephalic vein to the petrosal sinus (light blue arrows), ultimately into the sigmoid sinus. The middle and posterior segments are absent (normal course is illustrated by the pink dotted line).