Angiography, Digital SubtractionSubtraction TechniqueMagnetic Resonance AngiographyCerebral AngiographyAngiographyIntracranial AneurysmCoronary AngiographyRadiographic Image EnhancementImaging, Three-DimensionalContrast MediaTomography, X-Ray ComputedIntracranial Arteriovenous MalformationsSensitivity and SpecificityEmbolization, TherapeuticCarotid Artery, InternalImage Processing, Computer-AssistedAneurysm, RupturedCentral Nervous System Vascular MalformationsReproducibility of ResultsArterial Occlusive DiseasesCarotid StenosisTomography, Spiral ComputedSubarachnoid HemorrhageCerebral VeinsIohexolSalivary Gland CalculiFluorescein AngiographyObserver VariationIopamidolUltrasonography, Doppler, ColorUltrasonography, Doppler, DuplexConstriction, PathologicPredictive Value of TestsRadiographic Image Interpretation, Computer-AssistedRadiography, Dental, DigitalRetrospective StudiesArteriovenous MalformationsCerebral ArteriesMagnetic Resonance ImagingVertebrobasilar InsufficiencyX-Ray Intensifying ScreensArtifactsProspective StudiesCarotid Artery DiseasesGadolinium DTPAAnterior Cerebral ArteryTreatment OutcomeTriiodobenzoic AcidsVertebral ArteryCarotid-Cavernous Sinus FistulaImage EnhancementSurgical InstrumentsTibial ArteriesCerebrovascular DisordersCranial SinusesVasospasm, IntracranialRadiography, InterventionalArteriovenous FistulaAneurysmBasilar ArteryUltrasonography, Doppler, TranscranialInjections, Intra-ArterialSialographyFollow-Up StudiesMyelographyCerebrovascular CirculationCircle of WillisTime FactorsNeurosurgical ProceduresRenal ArteryFeasibility StudiesCerebral RevascularizationUltrasonographyIothalamate MeglumineCarotid ArteriesSalivary Gland DiseasesIntracranial ArteriosclerosisRadiation DosageBlood Flow VelocityRadiography, BitewingCarotid Artery, ExternalMoyamoya DiseaseSeverity of Illness IndexRadionuclide AngiographyPhantoms, ImagingAortographyVascular PatencyStentsCollateral CirculationUltrasonography, DopplerGadoliniumAngioplasty, BalloonSialadenitisIschemic Attack, TransientFalse Negative ReactionsImmediate Dental Implant LoadingFalse Positive ReactionsPreoperative CarePopliteal ArteryCerebrospinal Fluid Rhinorrhea