PhotonsTomography, Emission-Computed, Single-PhotonTomography, X-Ray ComputedTomography, Emission-ComputedPositron-Emission TomographyTomographyOrganotechnetium CompoundsRadiopharmaceuticalsTechnetium Tc 99m ExametazimeThallium RadioisotopesOximesTomography, Optical CoherenceIofetamineFluorodeoxyglucose F18TechnetiumIodine RadioisotopesTomography, OpticalCerebrovascular CirculationTomography, Spiral ComputedTechnetium Tc 99m SestamibiIodobenzenesBrainThalliumXenon RadioisotopesSensitivity and SpecificityMultidetector Computed TomographyPhantoms, ImagingMagnetic Resonance ImagingTechnetium Tc 99m PyrophosphateImage Processing, Computer-AssistedDiagnostic ImagingMultimodal ImagingCone-Beam Computed TomographyElectron Microscope TomographyTropanesOtoacoustic Emissions, SpontaneousAmphetaminesMyocardial Perfusion ImagingCardiac-Gated Single-Photon Emission Computer-Assisted TomographyReproducibility of ResultsTomography, X-RayFluorine RadioisotopesHeartImaging, Three-DimensionalRadioisotopesPredictive Value of TestsRadiationAcetazolamideTomography Scanners, X-Ray ComputedLightVehicle EmissionsTime FactorsOrganometallic CompoundsImage EnhancementOrganophosphorus CompoundsRadioactive TracersRadiation DosageGamma CamerasScattering, RadiationExercise TestRetinal Rod Photoreceptor CellsMolecular ImagingSpectrometry, FluorescenceEquipment DesignDopamine Plasma Membrane Transport ProteinsMonte Carlo MethodRadionuclide ImagingCarbon RadioisotopesCinanserinIndium RadioisotopesFrontal LobeAlgorithmsCoronary AngiographyNitrogen RadioisotopesTechnetium Tc 99m MedronateRegional Blood FlowRadiusTechnology, RadiologicThalamic DiseasesNortropanesTissue DistributionGallium RadioisotopesDipyridamoleSpectrometry, GammaContrast MediaVision, OcularFlumazenilCerebral RevascularizationCoronary CirculationRetrospective StudiesSpondylolysisProspective StudiesRadiometryTreatment OutcomeModels, StructuralRhodopsinTissue SurvivalDominance, CerebralFluorescent DyesCoronary Artery Disease