Fig. 2

Images of preoperative cerebral angiography of the dolichoectatic OA and the test of balloon occlusion. Preoperative cerebral angiography showed the dolichoectatic left ophthalmic artery (OA). Lateral projection of the left internal carotid arteriography (ICAG) revealed that the frontal branch of the middle meningeal artery (MMA) (arrowhead) was supplied from the dilated OA via the anastomotic artery (arrow) between OA and MMA (A). Maximum intensity projection (MIP) images obtained from the left ICAG showed that the OA was tortuous and dilated in the optic canal (B: axial, C: coronal). Left ECAG with balloon occlusion of the left ICA at the C3 segment revealed retrograde visualization of the proximal segment of the OA and central retinal arteries via the MMA (D: early phase, E: late phase) and central retinal arteries (black arrowhead). A retinal crescent (asterisk) was observed at the late venous phase (F)