Cerebrovascular CirculationXenon RadioisotopesRegional Blood FlowTomography, Emission-ComputedTechnetium Tc 99m ExametazimeBrainIofetamineTomography, Emission-Computed, Single-PhotonXenonOximesBlood Flow VelocityOxygen RadioisotopesOrganotechnetium CompoundsCerebral ArteriesAcetazolamideAmphetaminesCerebral InfarctionBlood VolumeBrain IschemiaAntipyrineCarbon DioxideCerebrovascular DisordersBlood Circulation TimeMagnetic Resonance ImagingIntracranial PressureKryptonMiddle Cerebral ArteryCerebral CortexIschemic Attack, TransientLaser-Doppler FlowmetryBlood PressureImage Processing, Computer-AssistedOxygenAutoradiographyReference ValuesUltrasonography, Doppler, TranscranialHypercapniaBrain MappingRadiopharmaceuticalsHyperventilationPositron-Emission TomographyFrontal LobeDominance, CerebralOxygen ConsumptionPartial PressurePapioSubarachnoid HemorrhageMicrospheresElectroencephalographyBrain EdemaTomography, X-Ray ComputedTime FactorsVascular ResistanceHemodynamicsInfarction, Middle Cerebral ArterySpin LabelsRadioisotopesBlood Gas AnalysisFunctional LateralityCarbon RadioisotopesArterial Occlusive DiseasesHemodilutionHypoxia, BrainNitrous OxideReperfusionBlood-Brain BarrierOccipital LobeRestCerebral AngiographyBrain DiseasesParietal LobeIodine RadioisotopesPerfusion ImagingCarotid Artery, InternalEchoencephalographyPia MaterTechnetiumBasal GangliaHomeostasisNimodipineHypotensionCatsRats, Inbred StrainsCerebral Arterial DiseasesBlood Volume DeterminationDogsThalamusCortical Spreading DepressionGlucoseMoyamoya DiseaseCarbonic Anhydrase InhibitorsGerbillinaeIntracranial Embolism and ThrombosisMagnetic Resonance AngiographyCerebral RevascularizationCarotid ArteriesIsofluraneCerebral HemorrhageReproducibility of ResultsRats, Sprague-Dawley