Suprachiasmatic perspective of anterior cerebral arteries. At the top of the image, the optic nerves are passing from the orbit through the optic canals. The frontal lobe has been reflected posteriorly to view the anterior components of the cerebral artery vasculature. The A1 segments of the anterior cerebral artery can be seen branching from the internal carotid arteries superior to the optic chiasm, proximal to the anterior communicating artery. The A2 segments of the anterior cerebral arteries continue distal to the anterior communicating artery and pass between the cerebral hemispheres at the frontal poles. (Image courtesy of AL Rhoton, Jr.)