Carotid Angiography with Cadaveric Correlate. A, Carotid angiography, AP view. The small red arrowheads indicate the M2 segment of the MCA. The green arrowheads indicate the M3 segment of the MCA over the planum polare. The green arrows indicate the M3 segment of the MCA over the planum temporale. The blue arrowheads indicate the M4 segment of the MCA over the parietal area. The blue arrows indicate the location of the intraparietal sulcus. The purple arrow indicates the superior limiting sulcus of insula. The large red arrowhead indicates the projection of the location of the tip of the pars triangularis, just distal to the genu of the MCA. B, Medial view of the right cerebral hemisphere with the crus cerebri removed to display the trajectory of the M1 segment in this projection. 1, thalamus; 2, M1 segment of the MCA; 3, uncus and the inferior choroidal point; 4, anterior cerebral artery; 5, anterior choroidal artery; 6, P2A segment of posterior cerebral artery; 7, posterior communicating artery; 8, P1 segment of posterior cerebral artery; 9, supraclinoid carotid artery. C, Carotid angiography, lateral view. The red arrows indicate anterior limiting sulcus. Blue arrows indicate superior limiting sulcus. The green arrows indicate inferior limiting sulcus. M, sylvian point. (Images courtesy of AL Rhoton, Jr.)