Basilar ArteryIntracranial AneurysmMiosisAneurysmVertebrobasilar InsufficiencyAneurysm, RupturedEmbolization, TherapeuticVertebral ArteryCerebral AngiographyPosterior Cerebral ArteryArteriesSubarachnoid HemorrhageInfarction, Posterior Cerebral ArteryCerebral ArteriesBrain Stem InfarctionsTomography, X-Ray ComputedMagnetic Resonance AngiographyAneurysm, InfectedCoronary AneurysmCarotid Artery, InternalSplenic ArteryIliac AneurysmCerebrovascular CirculationAnterior Cerebral ArteryRenal ArteryAneurysm, DissectingAngiography, Digital SubtractionAortic AneurysmTreatment OutcomePulmonary ArteryCerebral InfarctionAngiographyIntracranial ArteriosclerosisBrain InfarctionVertebral Artery DissectionCarotid ArteriesFemoral ArteryIliac ArteryMoyamoya DiseaseBlood Vessel Prosthesis ImplantationStentsVasospasm, IntracranialArterial Occlusive DiseasesCarotid Artery DiseasesStrokeAortic Aneurysm, ThoracicMagnetic Resonance ImagingPopliteal ArteryRetrospective StudiesHeart AneurysmMesenteric ArteriesSubclavian ArteryCeliac ArteryBrain IschemiaFollow-Up StudiesVascular Surgical ProceduresHepatic ArteryUltrasonography, Doppler, TranscranialMesenteric Artery, SuperiorIschemic Attack, TransientEndovascular ProceduresVasodilationAneurysm, FalseCerebral RevascularizationCircle of WillisVasoconstrictionBlood Vessel ProsthesisConstriction, PathologicBronchial ArteriesCoronary Artery BypassIntracranial EmbolismMuscle, Smooth, VascularMiddle Cerebral ArteryRadial ArteryCerebrovascular DisordersOphthalmic ArteryDogsCranial Fossa, PosteriorMucocutaneous Lymph Node SyndromeVasodilator AgentsTime FactorsMammary ArteriesSurgical InstrumentsCerebellumAcute DiseaseCoronary VesselsCarotid Artery, CommonRisk FactorsProspective StudiesBrachial ArteryAorta, AbdominalSerotoninUlnar ArteryRupture, SpontaneousTemporal ArteriesDilatation, PathologicRecurrenceNeurosurgical ProceduresVascular PatencyAortography