Medically reviewed by Nicholas R. Metrus, MD The posterior communicating artery (PCOM) is a part of a group of arteries in the brain known as the circle of Willis. The artery connects the internal ...

Watershed Infarction: Axial CT scan.Note the large hypodensity in the left basal ganglia and internal capsule. Although watershed infarcts are most often thought of as areas between two major blood ...