Right Interventricular Foramen of Monro. The image is set within the body of the lateral ventricle. The septum pellucidum forms the medial wall of the ventricle (top of image). The thalamostriate vein is visible draining to the venous angle then to the internal cerebral vein along the third ventricle. The choroidal vein is visible draining to the venous angle along with the choroid plexus. (Image courtesy of AL Rhoton, Jr.)