Cerebrovascular CirculationPerfusionIntracranial PressurePerfusion ImagingCerebral ArteriesOximesTechnetium Tc 99m ExametazimeMiddle Cerebral ArteryBrainCerebral InfarctionOrganotechnetium CompoundsTomography, Emission-Computed, Single-PhotonCirculatory Arrest, Deep Hypothermia InducedIntracranial HypertensionBlood Flow VelocityBrain IschemiaCerebral AngiographyCerebral PalsyUltrasonography, Doppler, TranscranialMyocardial Perfusion ImagingRegional Blood FlowMagnetic Resonance ImagingCerebrumBrain InjuriesInfarction, Middle Cerebral ArteryCerebrovascular DisordersIofetamineHypothermia, InducedBlood PressureSubarachnoid HemorrhageAcetazolamideSpectroscopy, Near-InfraredHeart Arrest, InducedBrain DiseasesBlood VolumeMagnetic Resonance AngiographyTomography, X-Ray ComputedMonitoring, PhysiologicCardiopulmonary BypassOxygenCerebral HemorrhageAxillary ArteryTomography, Emission-ComputedAortic Aneurysm, ThoracicMalaria, CerebralBrain EdemaCerebral VeinsIschemic Attack, TransientHypoxia, BrainVasospasm, IntracranialTime FactorsAneurysm, DissectingAorta, ThoracicCarbon DioxideHemodynamicsLaser-Doppler FlowmetryXenon RadioisotopesMonitoring, IntraoperativeExtracorporeal CirculationAortic AneurysmHomeostasisMoyamoya DiseaseContrast MediaImage Processing, Computer-AssistedCraniocerebral TraumaXenonRadiopharmaceuticalsCerebral RevascularizationAmphetaminesBlood Gas AnalysisStrokeGlasgow Outcome ScaleOxygen ConsumptionReperfusionCarotid Artery, InternalGlasgow Coma ScaleHypocapniaArterial Occlusive DiseasesMicrocirculationTreatment OutcomeSpin LabelsEchoencephalographyOxygen RadioisotopesDisease Models, AnimalChemotherapy, Cancer, Regional PerfusionRats, Sprague-DawleyCraniotomyCarotid StenosisHypotensionBrachiocephalic TrunkCoronary CirculationVascular ResistanceBrain DeathImage EnhancementMicrodialysisDominance, CerebralDogsBlood Vessel Prosthesis ImplantationProspective StudiesSensitivity and Specificity