Noninvasive VentilationRespiratory InsufficiencySensitivity and SpecificityMagnetic Resonance ImagingDiagnostic ImagingReproducibility of ResultsPositive-Pressure RespirationContrast MediaPredictive Value of TestsMonitoring, PhysiologicPositron-Emission TomographyMolecular ImagingSpectroscopy, Near-InfraredBlood Flow VelocityUltrasonographyTomography, X-Ray ComputedMasksRadiopharmaceuticalsRespiration, ArtificialImage Processing, Computer-AssistedFeasibility StudiesMagnetic Resonance AngiographyElasticity Imaging TechniquesBreath TestsTime FactorsEquipment DesignOximetryUltrasonicsProspective StudiesImage Interpretation, Computer-AssistedPrenatal DiagnosisTechnetiumTomography, Emission-ComputedImaging, Three-DimensionalMaternal Serum Screening TestsFluorine RadioisotopesBiological MarkersLuminescent MeasurementsBlood Pressure DeterminationEchocardiography, DopplerOxygenPlethysmographyIntubation, IntratrachealTomography, Emission-Computed, Single-PhotonCardiography, ImpedanceVentilators, MechanicalMagnetic Resonance SpectroscopyROC CurveImage EnhancementNeuromuscular DiseasesIntermittent Positive-Pressure VentilationThermographyEchocardiographyDisease Models, AnimalExhalationElectrocardiographyUltrasonic TherapyVentilator WeaningModels, CardiovascularSignal Processing, Computer-AssistedPlethysmography, ImpedanceBlood PressureObesity Hypoventilation SyndromeCoronary AngiographyBody Surface Potential MappingAlgorithmsHigh-Intensity Focused Ultrasound AblationCerebrovascular CirculationTransducersBlood Pressure MonitorsBrainTreatment OutcomeCoronary CirculationWhole Body ImagingPhotoacoustic TechniquesBiopsyRegional Blood FlowReference ValuesSeverity of Illness IndexLuciferases, FireflyOxygen Inhalation TherapyDiagnostic Techniques, CardiovascularMicrobubblesPulseOptical ImagingHypercapniaHeartHemodynamicsUltrasonography, DopplerDogsSpectrum Analysis, RamanGadolinium DTPAWork of BreathingPhotoplethysmographyCopper RadioisotopesOxygen RadioisotopesCarbon DioxidePulmonary Disease, Chronic ObstructiveAcute DiseaseLiver Cirrhosis