Anterior Cerebral ArteryInfarction, Anterior Cerebral ArteryCerebral ArteriesCerebral AngiographyIntracranial AneurysmMiddle Cerebral ArteryCircle of WillisCerebral Arterial DiseasesCerebral InfarctionInfarction, Middle Cerebral ArterySubarachnoid HemorrhageAneurysm, RupturedCerebrovascular CirculationTomography, X-Ray ComputedCarotid Artery, InternalUltrasonography, Doppler, TranscranialBasilar ArteryMagnetic Resonance AngiographyBrain IschemiaBlood Flow VelocityCerebral RevascularizationEchoencephalographyIntracranial Embolism and ThrombosisArteriesVasospasm, IntracranialIschemic Attack, TransientCarotid ArteriesBrainAngiography, Digital SubtractionNeurosurgical ProceduresArterial Occlusive DiseasesIntracranial Arteriovenous MalformationsBrain Hemorrhage, TraumaticEmbolization, TherapeuticVertebral ArteryPosterior Cerebral ArteryDominance, CerebralCraniotomyAkinetic MutismIntracranial ArteriosclerosisCerebrovascular DisordersMoyamoya DiseaseCerebral HemorrhageMagnetic Resonance ImagingAneurysm, DissectingSurgical InstrumentsUltrasonography, DopplerCollateral CirculationStrokeTreatment OutcomeRegional Blood FlowHematomaCarotid StenosisPulmonary ArteryUltrasonographyFrontal LobeCerebral PalsyCarotid Artery DiseasesMesenteric ArteriesRenal ArteryFemoral ArteryRetrospective StudiesHematoma, SubduralPostoperative ComplicationsIntracranial EmbolismTemporal ArteriesFollow-Up StudiesBrain EdemaTime FactorsCerebral VeinsInfarction, Posterior Cerebral ArteryInfant, NewbornVasoconstriction