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 RevascularizationEchoencephalographyArteriesIntracranial Embolism and ThrombosisVasospasm, IntracranialIschemic Attack, TransientCarotid ArteriesBrainNeurosurgical ProceduresArterial Occlusive DiseasesAngiography, Digital SubtractionIntracranial Arteriovenous MalformationsBrain Hemorrhage, TraumaticEmbolization, TherapeuticVertebral ArteryPosterior Cerebral ArteryDominance, CerebralCraniotomyAkinetic MutismIntracranial ArteriosclerosisCerebrovascular DisordersMoyamoya DiseaseCerebral HemorrhageMagnetic Resonance ImagingAneurysm, DissectingSurgical InstrumentsUltrasonography, DopplerTreatment OutcomeCollateral CirculationRegional Blood FlowStrokeHematomaPulmonary ArteryFrontal LobeUltrasonographyCarotid StenosisCerebral PalsyCarotid Artery DiseasesRetrospective StudiesRenal ArteryFemoral ArteryMesenteric ArteriesTime FactorsFollow-Up StudiesHematoma, SubduralPostoperative ComplicationsIntracranial EmbolismTemporal ArteriesBrain EdemaCerebral VeinsInfant, NewbornInfarction, Posterior Cerebral ArteryVasoconstrictionHemodynamicsNeurologic ExaminationCoronary Artery Bypass