Magnetic Resonance AngiographyMagnetic Resonance ImagingAngiography, Digital SubtractionAngiographyContrast MediaCerebral AngiographyImaging, Three-DimensionalGadoliniumCoronary AngiographyGadolinium DTPAMagnetic Resonance SpectroscopySensitivity and SpecificityArteriesCarotid Artery, InternalImage EnhancementCerebral ArteriesCircle of WillisTomography, X-Ray ComputedVertebral ArteryCarotid StenosisArterial Occlusive DiseasesUltrasonography, Doppler, DuplexIntracranial AneurysmRenal Artery ObstructionConstriction, PathologicCerebral Arterial DiseasesRenal ArteryCarotid ArteriesVertebrobasilar InsufficiencyImage Interpretation, Computer-AssistedArtifactsPredictive Value of TestsObserver VariationReproducibility of ResultsImage Processing, Computer-AssistedMagnetic Resonance Imaging, CinePulmonary ArteryBasilar ArteryAnterior Cerebral ArteryProspective StudiesPosterior Cerebral ArteryOrganometallic CompoundsIliac ArteryMeglumineCoronary VesselsCarotid Artery DiseasesIntracranial Arteriovenous MalformationsCerebrovascular CirculationPulmonary VeinsIntracranial Arterial DiseasesEndarterectomy, CarotidUltrasonography, Doppler, ColorPreoperative CareIntracranial ArteriosclerosisFemoral ArteryTreatment OutcomeRetrospective StudiesCeliac ArteryBrainUltrasonography, Doppler, TranscranialVertebral Artery DissectionCarotid Artery, ExternalSeverity of Illness IndexInfarction, Posterior Cerebral ArteryCollateral CirculationEmbolization, TherapeuticAneurysm, RupturedMiddle Cerebral ArteryStentsFeasibility StudiesUltrasonography, DopplerPeripheral Vascular DiseasesTime FactorsCerebrovascular DisordersTibial ArteriesScimitar SyndromeVascular MalformationsMoyamoya DiseaseBlood Flow VelocityFibromuscular DysplasiaFollow-Up StudiesPortographyLegFluorescein AngiographyVascular PatencyStrokeAortographyRadiographic Image EnhancementDiagnostic ImagingLateral Medullary SyndromeBrain IschemiaPhlebographyIschemic Attack, TransientInfarction, Middle Cerebral ArteryIncidental FindingsHypertension, RenovascularEcho-Planar ImagingCerebral VeinsTakayasu ArteritisCerebral Infarction