Subclavian steal from the circle of Willis.
D000792:Angiography; D001488:Basilar Artery; D001775:Blood Circulation; D002339:Carotid Arteries; D002941:Circle of Willis / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008875:Middle Aged; D013349:Subclavian Steal Syndrome / Q000503:physiopathology*; D014711:Vertebral Artery