PhotonsTomography, Emission-Computed, Single-PhotonElementary ParticlesScattering, RadiationRadiometryPhantoms, ImagingLightMonte Carlo MethodScintillation CountingMicroscopy, Fluorescence, MultiphotonOrganotechnetium CompoundsParticle AcceleratorsRadiation DosageRadiopharmaceuticalsTechnetium Tc 99m ExametazimeThallium RadioisotopesTechnetiumTomography, Emission-ComputedOximesEquipment Failure AnalysisRadiotherapy Planning, Computer-AssistedRelative Biological EffectivenessEquipment DesignTelluriumRadiotherapy, High-EnergyRadiotherapy DosageIodine RadioisotopesTomography, OpticalProton TherapySemiconductorsOptical ProcessesOptics and PhotonicsGamma CamerasLasersPhotometryRadioisotopesIofetamineRadiationDose-Response Relationship, RadiationElectronsSpectrometry, GammaImage Processing, Computer-AssistedLuminescent MeasurementsLutetiumCadmium CompoundsSynchrotronsDiagnostic ImagingRetinal Rod Photoreceptor CellsHeavy Ion RadiotherapyQuantum TheoryPositron-Emission TomographyRhodopsinRadionuclide ImagingThalliumLuminescenceComputer SimulationXenon RadioisotopesLinear Energy TransferX-RaysSpectrum AnalysisTechnetium Tc 99m SestamibiSensitivity and SpecificityRadiotherapy, Intensity-ModulatedVision, OcularTechnetium Tc 99m PyrophosphatePhotoreceptor CellsPhotosynthesisIodobenzenesNeutronsFluorescenceX-Ray TherapyTomography, X-Ray ComputedComputer-Aided DesignCerebrovascular CirculationRadiotherapy, ConformalReproducibility of ResultsAlgorithmsTime FactorsModels, TheoreticalProtonsAstronomical ObjectsSpectrometry, FluorescenceTomographyRadiusPhotochemistryFast NeutronsHeavy IonsDarknessBrainOrgans at RiskModels, StructuralMolecular ImagingImage EnhancementMineralsTropanesDark Adaptation