Blood VolumePlasma VolumeHypovolemiaErythrocyte VolumeCerebrovascular CirculationHematocritPlasma SubstitutesMagnetic Resonance ImagingHemodynamicsStroke VolumeFluid ShiftsHydrogen-Ion ConcentrationLung Volume MeasurementsRegional Blood FlowCardiac OutputBrainBlood PressurePulmonary Diffusing CapacityHemorrhageHemodilutionContrast MediaBlood CirculationOxygenDye Dilution TechniqueHemoglobinsBlood Flow VelocityReproducibility of ResultsIsotonic SolutionsHydroxyethyl Starch DerivativesSpectroscopy, Near-InfraredTime FactorsShock, HemorrhagicImage Processing, Computer-AssistedPerfusion ImagingIndocyanine GreenDogsPulmonary CirculationMagnetic Resonance AngiographyBlood Volume DeterminationOxygen RadioisotopesOxygen ConsumptionTemperatureVascular CapacitanceTomography, X-Ray ComputedGadolinium DTPATomography, Emission-ComputedSodium ChlorideHypotensionHeart RateFluid TherapySensitivity and SpecificityThoraxCarbon DioxideMicrocirculationVascular ResistanceBrain NeoplasmsExchange Transfusion, Whole BloodImage Interpretation, Computer-AssistedKineticsPlethysmographyImage EnhancementPolygelineImaging, Three-DimensionalSplanchnic CirculationOrgan SizeCentral Venous PressureWater-Electrolyte BalanceIndicator Dilution TechniquesForced Expiratory VolumeAcetazolamideReference ValuesColoring AgentsLiver CirculationCarbon MonoxideTechnetiumDiuresisPosturePressureAlgorithmsSaline Solution, HypertonicBrain IschemiaSupine PositionBody WaterEcho-Planar ImagingBlood Gas AnalysisLungCapillariesSubstrate SpecificityValsalva ManeuverOsmolar ConcentrationPressoreceptorsPlethysmography, ImpedanceShockProspective StudiesVeinsCapillary PermeabilityHyperventilationColloidsResuscitationVasopressins