Coronary AngiographyMultidetector Computed TomographyTomography, X-Ray ComputedCoronary Artery DiseaseRadiographic Image Interpretation, Computer-AssistedCoronary StenosisRadiation DosageAngiographyCoronary VesselsVascular CalcificationCerebral AngiographyIohexolPlaque, AtheroscleroticRadiographic Image EnhancementMyocardial Perfusion ImagingCardiac-Gated Imaging TechniquesAngiography, Digital SubtractionMagnetic Resonance AngiographyContrast MediaPredictive Value of TestsReproducibility of ResultsSensitivity and SpecificityCoronary CirculationTomography, Spiral ComputedSeverity of Illness IndexAngioplasty, Balloon, CoronaryProspective StudiesElectrocardiographyExamination TablesCoronary Artery BypassChi-Square DistributionIntracranial AneurysmCoronary DiseasePrognosisImaging, Three-DimensionalIopamidolCalcinosisImage Processing, Computer-AssistedMyocardial RevascularizationCoronary VasospasmFluorescein AngiographyCoronary AneurysmMyocardial InfarctionVertebrobasilar InsufficiencyRetrospective StudiesCarotid Artery, InternalStentsTreatment OutcomeCoronary ThrombosisObserver VariationRisk AssessmentCoronary RestenosisIntracranial Arteriovenous MalformationsCarotid StenosisRisk FactorsVertebral ArterySubarachnoid HemorrhageFollow-Up StudiesCoronary OcclusionPerfusion ImagingEmbolization, TherapeuticAneurysm, RupturedTime FactorsPercutaneous Coronary InterventionCerebral ArteriesCollateral CirculationCerebral VeinsCircle of WillisCeliac ArteryFeasibility StudiesUltrasonography, InterventionalExtravasation of Diagnostic and Therapeutic MaterialsRadionuclide AngiographyAortographyArterial Occlusive DiseasesBasilar ArteryTriiodobenzoic AcidsTomography, Emission-Computed, Single-PhotonChest PainCentral Nervous System Vascular MalformationsConstriction, PathologicCarotid Artery DiseasesAcute DiseaseCoronary Care UnitsMyocardial IschemiaSubtraction TechniqueAcute Coronary SyndromeArtifactsStrokeInjections, Intra-ArterialIntracranial ArteriosclerosisCardiac CatheterizationCarotid ArteriesPhantoms, ImagingImage EnhancementAneurysm, FalseVasospasm, IntracranialAngina, UnstableCerebral HemorrhageVertebral Artery Dissection