Magnified view of venous anatomy of the lateral and third ventricles. The fornix is retracted medially in this image and the velum interpositum opened to reveal the major venous structures of the lateral and third ventricles. The superior choroidal vein courses with the choroid plexus of the lateral ventricle through the foramen of Monro to join the internal cerebral vein (ICV). The thalamostriate vein runs along the superior edge of the thalamus on the lateral ventricular wall adjacent to the caudate prior to draining into the ICV. The septal vein originates at the lateral aspect of the anterior horns of the lateral ventricles and pass medially and posteriorly to traverse the foramen of Monro and drain into the ICV. (Image courtesy of AL Rhoton, Jr.)