Circle of WillisAngiographyMagnetic Resonance AngiographyCerebral AngiographyCoronary AngiographyAngiography, Digital SubtractionCerebral ArteriesFluorescein AngiographyCollateral CirculationCarotid Artery, InternalTomography, X-Ray ComputedIntracranial AneurysmDNA, CircularVertebral ArteryManagement Quality CirclesContrast MediaCerebrovascular CirculationMoyamoya DiseaseImaging, Three-DimensionalNeuroendoscopyIntracranial Arteriovenous MalformationsBasilar ArteryIntracranial ArteriosclerosisCarotid StenosisDoppler EffectUltrasonography, Doppler, TranscranialSensitivity and SpecificityRadionuclide AngiographySubarachnoid HemorrhageArterial Occlusive DiseasesCarotid Artery, ExternalCoronary Artery DiseaseImage Processing, Computer-AssistedCoronary StenosisBlood Flow VelocityHistory, 17th CenturyTomography, Spiral ComputedSphenoid BoneProspective StudiesCerebrovascular DisordersEmbolization, TherapeuticCarotid Artery DiseasesCarotid ArteriesCerebral InfarctionCarotid-Cavernous Sinus FistulaOphthalmic ArteryPredictive Value of TestsArachnoidIopamidolUltrasonography, Doppler, ColorEchoencephalographyBrain IschemiaMultidetector Computed TomographyIschemic Attack, TransientReproducibility of ResultsSkull BaseCoronary VesselsRadiographic Image Interpretation, Computer-AssistedMigraine with AuraCranial Fossa, PosteriorCoronary DiseaseIohexolBrainTreatment OutcomeStentsCentral Nervous System Vascular MalformationsAneurysm, RupturedRetrospective StudiesIndocyanine GreenUltrasonographyConstriction, PathologicFollow-Up StudiesEndarterectomy, CarotidVertebrobasilar InsufficiencyObserver VariationDominance, CerebralPia MaterRadiographic Image EnhancementArteriovenous FistulaFundus OculiUltrasonography, InterventionalStrokeTime FactorsCerebral VeinsAngioplasty, Balloon, CoronaryFeasibility StudiesMagnetic Resonance ImagingSeverity of Illness IndexMyocardial InfarctionRegional Blood FlowArteriovenous MalformationsImage EnhancementCadaverTriiodobenzoic AcidsElectrocardiographyAngina PectorisAortographyRadiation DosageCardiac CatheterizationGadolinium DTPA