title: The competence of the circle of Willis in extra-cranial cerebrovascular atherosclerosis.
mesh_terms: D002340:Carotid Artery Diseases / Q000503:physiopathology*; D002343:Carotid Artery, Internal; D002560:Cerebrovascular Circulation; D002941:Circle of Willis / Q000503:physiopathology*; D003097:Collateral Circulation; D006801:Humans; D002537:Intracranial Arteriosclerosis / Q000503:physiopathology*