Anterior Cerebral ArteryInfarction, Anterior Cerebral ArteryCerebral ArteriesIntracranial AneurysmCerebral AngiographyAneurysm, RupturedMiddle Cerebral ArteryVertebral ArteryCircle of WillisSubarachnoid HemorrhageBasilar ArteryArteriesCerebral InfarctionCerebral Arterial DiseasesTomography, X-Ray ComputedInfarction, Middle Cerebral ArteryCerebrovascular CirculationCerebellumCerebellar DiseasesPosterior Cerebral ArteryMagnetic Resonance AngiographyEmbolization, TherapeuticCarotid Artery, InternalFenestration, LabyrinthCerebral RevascularizationUltrasonography, Doppler, TranscranialLateral Medullary SyndromeAneurysm, DissectingAngiography, Digital SubtractionNeurosurgical ProceduresIntracranial Arteriovenous MalformationsCarotid ArteriesVertebrobasilar InsufficiencyBrain IschemiaCraniotomyAkinetic MutismBlood Flow VelocityMagnetic Resonance ImagingBrain Stem InfarctionsIntracranial Embolism and ThrombosisEchoencephalographyVasospasm, IntracranialArterial Occlusive DiseasesSurgical InstrumentsIschemic Attack, TransientPulmonary ArteryHemifacial SpasmBrainTreatment OutcomeVertebral Artery DissectionRupture, SpontaneousBrain Hemorrhage, TraumaticRenal ArteryDominance, CerebralIntracranial ArteriosclerosisCerebrovascular DisordersMoyamoya DiseaseFemoral ArteryMesenteric ArteriesCerebral HemorrhageTrigeminal NeuralgiaUltrasonography, DopplerCaloric TestsMicrosurgeryFontan ProcedureRetrospective StudiesCarotid Artery DiseasesRegional Blood FlowVertigoBrain InfarctionCarotid StenosisFollow-Up StudiesStrokeCerebellopontine AngleUltrasonographyIliac ArteryCoronary Artery BypassImaging, Three-DimensionalCollateral CirculationHematomaRadial ArteryFacial Nerve DiseasesMammary ArteriesFrontal LobeSubclavian ArteryTemporal ArteriesNerve Compression SyndromesTime FactorsPostoperative ComplicationsElectronystagmographyCarotid Artery, CommonCerebral PalsyBrachial ArterySplenic ArteryUmbilical ArteriesVasoconstrictionCranial Fossa, PosteriorCranial Nerve DiseasesHepatic ArteryCoronary Vessels