PFCr2

Persistent Fetal Circulation. Rostal-caudal MRA projection. A number of individuals have a normal anatomic variant known as a persistent fetal circulation, where the posterior cerebral artery (PCA) arises directly from the Posterior Communicating artery off of the carotid. This can be either unilateral or bilateral.. In the intracranial MRA above, note that both PCAs are arising directly from the internal carotid arteries (ICA) and not the basilar. In patients with this anatomy, one embolus at the top of the carotid can infarct the ipsilateral middle cerebral and posterior cerebral territories.