Anterior Cerebral ArteryInfarction, Anterior Cerebral ArteryBasilar ArteryCerebral ArteriesCerebral AngiographyIntracranial AneurysmVertebrobasilar InsufficiencyMiddle Cerebral ArteryCircle of WillisSubarachnoid HemorrhageCerebral InfarctionVertebral ArteryPosterior Cerebral ArteryCerebrovascular CirculationAneurysm, RupturedCerebral Arterial DiseasesMagnetic Resonance AngiographyInfarction, Posterior Cerebral ArteryTomography, X-Ray ComputedInfarction, Middle Cerebral ArteryArteriesCarotid Artery, InternalUltrasonography, Doppler, TranscranialBrain IschemiaEmbolization, TherapeuticIntracranial ArteriosclerosisMoyamoya DiseaseIschemic Attack, TransientCerebral RevascularizationCarotid ArteriesVasospasm, IntracranialAngiography, Digital SubtractionArterial Occlusive DiseasesBlood Flow VelocityBrainMagnetic Resonance ImagingIntracranial Embolism and ThrombosisBrain Stem InfarctionsStrokeBrain InfarctionCerebrovascular DisordersEchoencephalographyAneurysm, DissectingPulmonary ArteryNeurosurgical ProceduresTreatment OutcomeIntracranial Arteriovenous MalformationsBrain Hemorrhage, TraumaticDominance, CerebralCraniotomyIntracranial EmbolismVertebral Artery DissectionAkinetic MutismCerebral HemorrhageMesenteric ArteriesRetrospective StudiesFemoral ArteryRenal ArteryCollateral CirculationRegional Blood FlowUltrasonography, DopplerSurgical InstrumentsFollow-Up StudiesCarotid Artery DiseasesVasoconstrictionCarotid StenosisAngiographyVasodilationAcute DiseaseCoronary Artery BypassIliac ArteryUltrasonographyConstriction, PathologicHematomaMuscle, Smooth, VascularRadial ArteryFrontal LobeTime FactorsMammary ArteriesSubclavian ArteryTemporal ArteriesStentsVasodilator AgentsDogsProspective StudiesCarotid Artery, CommonPostoperative ComplicationsUmbilical ArteriesCoronary VesselsBrachial ArterySplenic ArteryCerebral PalsyRats, Sprague-DawleyOphthalmic ArteryHemodynamicsRisk FactorsDisease Models, AnimalHepatic ArteryBlood PressureBlood Circulation