cerebral artery inner diameter posterior cerebral artery inner diameter 2012-10-03T05:59:18Z JSmith PCA inner diameter The length of a line which crosses a transverse view of a posterior cerebral artery, passing through its center and ending on either side at the inner surface of the blood vessel wall. The posterior cerebral artery (PCA) is one of a pair of blood vessels that supply blood to the posterior aspect, i.e. the occipital lobe, of the brain. posterior cerebral artery lumen diameter