Deep venous drainage into the basal vein. The basal vein of Rosenthal is formed by the convergence of the deep middle cerebral vein and the anterior cerebral vein within the crural cistern. The deep middle cerebral veins course deeply within the sylvian fissure to drain the insular cortex. The anterior cerebral veins drain the orbitofrontal cortex and accompany the anterior cerebral artery; the optic chiasm has been reflected to visualize the anterior cerebral veins. The basal vein runs directly beneath the optic tract and medial to the uncus. Interpeduncular veins drain the midbrain and lie medial to the oculomotor nerve. The basal vein collects tributaries from the pulvinar of the thalamus as it courses posteriorly to drain into the great cerebral vein of Galen. (Image courtesy of AL Rhoton, Jr.)