Anterior cerebral artery (ACA) aneurysms are divided into five groups which include:
4.- Classical pericallosal artery aneurysm or A3 aneurysms curving around the genu
5.- A4 aneurysm
6.- A5 aneurysms which include distal branch aneurysms.
Weisberg reviewed the CT findings in 40 patients with ruptured aneurysms of the anterior cerebral or anterior communicating artery. Within 3 days of the ictus, the common patterns included blood in the pericallosal cistern and interhemispheric fissure, blood in the caval-septal region, unilateral or bilateral frontal hematoma, and diffuse symmetric intraventricular and basal cisternal blood 1).