Tomography, X-Ray ComputedPositron-Emission TomographyTomography Scanners, X-Ray ComputedTomography, Emission-ComputedTomographyTomography, Optical CoherencePhantoms, ImagingTomography, Emission-Computed, Single-PhotonFluorodeoxyglucose F18Tomography, Spiral ComputedMagnetic Resonance ImagingTomography, OpticalMultidetector Computed TomographyImage Processing, Computer-AssistedCone-Beam Computed TomographyImaging, Three-DimensionalReproducibility of ResultsSensitivity and SpecificityElectron Microscope TomographyEquipment DesignFluorine RadioisotopesOtoacoustic Emissions, SpontaneousRadiopharmaceuticalsTomography, X-RayImage EnhancementEquipment Failure AnalysisBrainArtifactsRadiographic Image Interpretation, Computer-AssistedGermaniumRadiation DosageVehicle EmissionsAlgorithmsMultimodal ImagingImage Interpretation, Computer-AssistedRadiographic Image EnhancementContrast MediaLutetiumDiagnostic ImagingWhole Body ImagingCarbon RadioisotopesSubtraction TechniquePredictive Value of TestsUltrasonographyX-Ray MicrotomographyTransducersTime FactorsFeasibility StudiesCerebrovascular CirculationRadiometryGamma CamerasSilicatesObserver VariationSpectrometry, FluorescenceGreenhouse EffectCalibrationRetrospective StudiesMyocardial Perfusion ImagingFour-Dimensional Computed TomographyOrganotechnetium CompoundsProspective StudiesSignal-To-Noise RatioBrain MappingRadiography, AbdominalRadioactive TracersCoronary AngiographyRadioisotopesRadiography, ThoracicCopper RadioisotopesCarbon FootprintTreatment OutcomePhotonsScattering, RadiationReference ValuesOxygen RadioisotopesDeoxyglucoseTissue DistributionAir PollutantsCoronary Artery DiseaseAcousticsAnatomy, Cross-SectionalComputer-Aided DesignCalcinosisGallium RadioisotopesThallium RadioisotopesFluorescenceNuclear MedicineTechnology, RadiologicHeartOptics and PhotonicsMonte Carlo MethodMiniaturizationMethanePerfusion ImagingModels, TheoreticalRadionuclide ImagingFluorescent DyesMagnetic Resonance Imaging, InterventionalLung NeoplasmsIodine Radioisotopes