Left Interventricular Foramen of Monro. The image is set within the body of the left lateral ventricle. The stria terminalis courses rostrally in the ventrolateral floor of the ventricle in a narrow groove between the body of the caudate and the thalamus. The column of the fornix sweeps inferiorly and posteriorly to form the anterior wall of the foramen of Monro.  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.)