Cerebrovascular CirculationRegional Blood FlowXenon RadioisotopesBlood Flow VelocityTomography, Emission-ComputedTechnetium Tc 99m ExametazimeBrainTomography, Emission-Computed, Single-PhotonIofetamineXenonOxygen RadioisotopesOximesOrganotechnetium CompoundsCerebral ArteriesMicrospheresAcetazolamideBlood VolumeCarbon DioxideAmphetaminesBlood PressureBrain IschemiaCerebral InfarctionAntipyrineLaser-Doppler FlowmetryHemodynamicsVascular ResistanceCerebrovascular DisordersBlood Circulation TimeMagnetic Resonance ImagingOxygenDogsIntracranial PressureMiddle Cerebral ArteryKryptonOxygen ConsumptionCerebral CortexIschemic Attack, TransientPartial PressureCardiac OutputReference ValuesRadioisotopesBlood Gas AnalysisUltrasonography, Doppler, TranscranialAutoradiographyBlood CirculationImage Processing, Computer-AssistedHypercapniaRadiopharmaceuticalsSplanchnic CirculationBrain MappingHyperventilationTime FactorsHeart RateCoronary CirculationPositron-Emission TomographyFrontal LobeDominance, CerebralPapioAnesthesiaRenal CirculationSubarachnoid HemorrhageBrain EdemaElectroencephalographyScandiumCatsLiver CirculationMicrocirculationInfarction, Middle Cerebral ArteryTomography, X-Ray ComputedIsofluraneRats, Inbred StrainsSpin LabelsArterial Occlusive DiseasesHemodilutionPulmonary CirculationCarbon RadioisotopesAnesthesia, InhalationFunctional LateralityRats, Sprague-DawleyReperfusionRestHypoxia, BrainNitrous OxideVasodilationModels, CardiovascularBlood-Brain BarrierOccipital LobeCerebral AngiographyVasodilator AgentsVasoconstrictionBrain DiseasesPerfusion ImagingParietal LobeCollateral CirculationHomeostasisIodine RadioisotopesPia MaterHypotensionEchoencephalographyTechnetium