Vertebral ArteryVertebrobasilar InsufficiencyBasilar ArteryVertebral Artery DissectionSubarachnoid Hemorrhage, TraumaticCerebral AngiographyMagnetic Resonance AngiographyIntracranial AneurysmArteriesAneurysm, DissectingAngioplasty, BalloonSubclavian ArteryStentsSubclavian Steal SyndromeCarotid ArteriesCerebral ArteriesPulmonary ArteryAngiography, Digital SubtractionCarotid Artery, InternalAngiographyArterial Occlusive DiseasesRenal ArteryFemoral ArteryMesenteric ArteriesVertigoTomography, X-Ray ComputedEmbolization, TherapeuticSubarachnoid HemorrhageCarotid Artery DiseasesLateral Medullary SyndromeIntracranial ArteriosclerosisAneurysm, RupturedMammary ArteriesIliac ArteryCoronary Artery BypassConstriction, PathologicCarotid Artery, CommonOccipital BoneCerebral InfarctionRadial ArteryIschemic Attack, TransientCerebellar DiseasesCerebrovascular CirculationIntracranial Embolism and ThrombosisTreatment OutcomeCerebrovascular DisordersCarotid Artery, Internal, DissectionCervical VertebraeBrain Stem InfarctionsUltrasonography, Doppler, TranscranialHemifacial SpasmEchoencephalographyCervical AtlasMagnetic Resonance ImagingBrain IschemiaNeck InjuriesCerebral RevascularizationSplenic ArteryBrachial ArteryFibromuscular DysplasiaInfarction, Posterior Cerebral ArteryHepatic ArteryAxisCarotid Artery, ExternalFollow-Up StudiesCarotid StenosisCircle of WillisPosterior Cerebral ArteryBrachiocephalic TrunkStrokeCoronary VesselsAngioplastyRetrospective StudiesCeliac ArteryAneurysm, FalseOphthalmic ArteryNerve Compression SyndromesHeadacheMesenteric Artery, SuperiorAneurysmCerebellumPetrous BoneUltrasonographyTrigeminal NeuralgiaBlood Flow VelocityUmbilical ArteriesMiddle Cerebral ArteryRenal Artery ObstructionThoracic ArteriesBrain InfarctionUltrasonography, Doppler, ColorTemporal ArteriesUltrasonography, DopplerCerebral Hemorrhage, TraumaticBronchial ArteriesArteriovenous FistulaRegional Blood FlowAtlanto-Axial JointCarotid Artery InjuriesTime Factors