The pericallosal artery is the distal portion of the anterior cerebral artery (ACA) that courses over the superior surface of the body of the corpus callosum in the pericallosal cistern. It gives off many small branches to the corpus callosum, forming the pericallosal moustache.
Some authors describe the pericallosal artery as the entire distal portion of the ACA beginning at the anterior communicating artery (segments A2 to A5), therefore even including the portion anterior to the lamina terminalis and the rostrum and genu of the corpus callosum . Other authors define it as the artery created at the bifurcation of the ACA near the genu of the corpus callosum after giving off the callosomarginal artery . However, the latter description is problematic as the callosomarginal artery is not visible on imaging or even absent in a significant minority of cases .