The pericallosal artery is the continuation of the anterior cerebral artery (ACA) and is named after the origin of the callosomarginal artery. As it courses over the superior surface of the corpus callosum (CC) in the pericallosal cistern it gives off many small branches to the CC, forming the pericallosal pial plexus (pericallosal moustache).
The segment of the anterior cerebral artery distal to the anterior communicating artery (A2 to A5) has also been called the pericallosal artery. The two first conical branches of the ACerA supplying the medial surface, the orbitofrontal and the frontopolar arteries, usually arise from the A2 segment. The segments A3 to A5 give rise to other cortical branches to supply the medial surface of the hemisphere.
The A3 segment is a frequent site of origin for the anterior, middle internal frontal, and callosomarginal arteries.
The paracentral artery frequently stems from the A4 segment.
The A5 segment gives rise to the superior and inferior parietal arteries. All the cortical branches arise more frequently from the pericallosal than from the callosomarginal artery.
The pericallosal arteries are sonographically visible since the first trimester in 3D ultrasound scans of fetuses found to have a normal corpus callosum at follow-up 1).
The PA can routinely be observed at the first-trimester evaluation with color Doppler ultrasonography using the mid-sagittal view of the fetal head. The presence of an abnormal vascular map of the PA by Doppler ultrasonography at 11-14 weeks raises the suspicion of Agenesis of the corpus callosum 2).
The use of 3-D power Doppler sonoangiography enables the precise demonstration of the normal variants of the fetal pericallosal artery with different origins of the callosomarginal artery. The knowledge of normal variants helps to detect pathological forms of the pericallosal artery 3).