title: Invited commentary.
authors.affiliation: Department of Surgery, University of Virginia Health Sciences Center, Box 800679, Charlottesville, VA 22908, USA. jak3r@virginia.edu
authors.forename: John
authors.initials: J
authors.lastname: Kern
mesh_terms: D001344:Autopsy; D002560:Cerebrovascular Circulation; D002941:Circle of Willis / Q000000981:diagnostic imaging*; D006801:Humans; D018810:Magnetic Resonance Angiography; D011859:Radiography; D013348:Subclavian Artery / Q000000981:diagnostic imaging* / Q000601:surgery*; D014711:Vertebral Artery / Q000000981:diagnostic imaging*