Vertebral ArteryVertebrobasilar InsufficiencyBasilar ArteryVertebral Artery DissectionCerebral AngiographySubarachnoid Hemorrhage, TraumaticMagnetic Resonance AngiographyIntracranial AneurysmAneurysm, DissectingArteriesAngioplasty, BalloonSubclavian ArteryStentsCarotid Artery, InternalCarotid ArteriesSubclavian Steal SyndromeCerebral ArteriesCarotid Artery DiseasesAngiography, Digital SubtractionIntracranial ArteriosclerosisPulmonary ArteryAngiographyArterial Occlusive DiseasesTomography, X-Ray ComputedCarotid Artery, ExternalRenal ArteryFemoral ArteryEmbolization, TherapeuticMesenteric ArteriesSubarachnoid HemorrhageVertigoCarotid StenosisLateral Medullary SyndromeCarotid Artery, CommonCerebrovascular DisordersConstriction, PathologicCarotid Artery, Internal, DissectionCerebral InfarctionIschemic Attack, TransientCerebrovascular CirculationUltrasonography, Doppler, TranscranialAneurysm, RupturedAneurysmTreatment OutcomeIntracranial Embolism and ThrombosisMammary ArteriesCerebral RevascularizationIliac ArteryEchoencephalographyCoronary Artery BypassMagnetic Resonance ImagingBrain IschemiaOccipital BoneStrokeRadial ArteryCerebellar DiseasesUltrasonographyCircle of WillisPosterior Cerebral ArteryFollow-Up StudiesRetrospective StudiesCervical VertebraeBrain Stem InfarctionsBrachiocephalic TrunkHemifacial SpasmAngioplastyCervical AtlasNeck InjuriesBlood Flow VelocitySplenic ArteryBrachial ArteryAneurysm, FalseDoppler EffectFibromuscular DysplasiaUltrasonography, Doppler, ColorOphthalmic ArteryHeadacheNeckInfarction, Posterior Cerebral ArteryTemporal ArteriesUltrasonography, Doppler, DuplexHepatic ArteryAxisMiddle Cerebral ArteryUltrasonography, DopplerCoronary VesselsCerebellumCeliac ArteryVascular Surgical ProceduresArteriosclerosisNerve Compression SyndromesMesenteric Artery, SuperiorRegional Blood FlowTime FactorsPetrous BoneProspective StudiesCarotid Artery InjuriesTrigeminal NeuralgiaUmbilical ArteriesCerebral Arterial Diseases