Anterior Cerebral ArteryInfarction, Anterior Cerebral ArteryBasilar ArteryCerebral ArteriesCerebral AngiographyIntracranial AneurysmMiddle Cerebral ArteryCircle of WillisSubarachnoid HemorrhageCerebral Arterial DiseasesCerebral InfarctionCerebrovascular CirculationInfarction, Middle Cerebral ArteryAneurysm, RupturedArteriesCarotid Artery, InternalTomography, X-Ray ComputedUltrasonography, Doppler, TranscranialVertebral ArteryMagnetic Resonance AngiographyCarotid ArteriesVasospasm, IntracranialBrain IschemiaBlood Flow VelocityIntracranial Embolism and ThrombosisArterial Occlusive DiseasesCerebral RevascularizationIschemic Attack, TransientAngiography, Digital SubtractionVertebrobasilar InsufficiencyEchoencephalographyEmbolization, TherapeuticBrainPosterior Cerebral ArteryIntracranial Arteriovenous MalformationsPulmonary ArteryNeurosurgical ProceduresIntracranial ArteriosclerosisBrain Hemorrhage, TraumaticCerebrovascular DisordersMagnetic Resonance ImagingCraniotomyDominance, CerebralAneurysm, DissectingAkinetic MutismMesenteric ArteriesCerebral HemorrhageMoyamoya DiseaseRenal ArteryFemoral ArteryUltrasonography, DopplerTreatment OutcomeSurgical InstrumentsRegional Blood FlowCarotid Artery DiseasesStrokeVasoconstrictionCarotid StenosisCollateral CirculationVasodilationIliac ArteryCoronary Artery BypassHematomaMuscle, Smooth, VascularRadial ArteryUltrasonographyMammary ArteriesFrontal LobeBrain Stem InfarctionsRetrospective StudiesSubclavian ArteryTemporal ArteriesTime FactorsCarotid Artery, CommonVasodilator AgentsFollow-Up StudiesCerebral PalsyBrachial ArterySplenic ArteryUmbilical ArteriesDogsIntracranial EmbolismCoronary VesselsHepatic ArteryOphthalmic ArteryPostoperative ComplicationsRats, Sprague-DawleyInfarction, Posterior Cerebral ArteryDisease Models, AnimalNeurologic ExaminationEndothelium, VascularCeliac ArteryMesenteric Artery, SuperiorVasoconstrictor AgentsHematoma, SubduralSerotoninHemodynamicsCarotid Artery, ExternalBlood PressureBrain Edema