title: Noninvasive imaging is improving but digital subtraction angiography remains the gold standard.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Hill
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Demchuk
authors.forename: Richard
authors.initials: R
authors.lastname: Frayne
mesh_terms: D015901:Angiography, Digital Subtraction / Q000592:standards*; D002536:Cerebral Arteries / Q000473:pathology / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology; D002561:Cerebrovascular Disorders / Q000175:diagnosis*; D003951:Diagnostic Errors / Q000517:prevention & control; D003952:Diagnostic Imaging / Q000379:methods / Q000592:standards* / Q000639:trends*; D006801:Humans; D002537:Intracranial Arteriosclerosis / Q000175:diagnosis; D018810:Magnetic Resonance Angiography / Q000592:standards / Q000706:statistics & numerical data / Q000639:trends; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D017585:Ultrasonography, Doppler, Transcranial / Q000592:standards / Q000706:statistics & numerical data / Q000639:trends