Collateral CirculationRegional Blood FlowBlood Flow VelocityCerebrovascular CirculationCoronary CirculationCollateral LigamentsCircle of WillisLiver CirculationArterial Occlusive DiseasesKidney CalicesCoronary AngiographyCerebral AngiographyAngiographyIschemiaCoronary OcclusionHypertension, PortalLigationHemodynamicsConstriction, PathologicCerebral ArteriesAngina PectorisMedial Collateral Ligament, KneeBalloon OcclusionCoronary VesselsCoronary DiseaseMagnetic Resonance AngiographyHindlimbBlood CirculationBlood PressureCineangiographyDogsDoppler EffectCeliac ArteryCarotid Artery, InternalFemoral ArteryLaser-Doppler FlowmetryAngioplasty, Balloon, CoronaryTime FactorsCerebral Arterial DiseasesCoronary StenosisBrain IschemiaPulmonary CirculationCarotid Artery, ExternalNeovascularization, PhysiologicArteriesMyocardial InfarctionMoyamoya DiseaseMyocardial IschemiaAngiography, Digital SubtractionCarotid StenosisVascular ResistanceElectrocardiographyInfarction, Middle Cerebral ArteryTomography, X-Ray ComputedCardiac CatheterizationPhlebographyBrainCerebral InfarctionFlow CytometryEmbolization, TherapeuticTreatment OutcomeCarotid ArteriesSplanchnic CirculationMicrospheresDisease Models, AnimalMagnetic Resonance ImagingExtracorporeal CirculationPulsatile FlowProspective StudiesCarotid Artery DiseasesCoronary Artery DiseaseMicrocirculationStrokeXenon RadioisotopesBlood Circulation TimeVasodilationFollow-Up StudiesRenal CirculationOxygenHyperemiaVasodilator AgentsOxygen ConsumptionUltrasonography, DopplerRetrospective StudiesSeverity of Illness IndexCarbon DioxideHeart RateRheologyPlacental CirculationUltrasonography, Doppler, ColorUltrasonography, Doppler, TranscranialTomography, Emission-ComputedCapillariesBlood VolumeVasoconstrictionModels, Cardiovascular