Tomography, X-Ray ComputedRetrospective StudiesMagnetic Resonance ImagingRadiopharmaceuticalsPositron-Emission TomographyReproducibility of ResultsSensitivity and SpecificityFluorodeoxyglucose F18Image Processing, Computer-AssistedRadionuclide ImagingImaging, Three-DimensionalGallium RadioisotopesTechnetiumWhole Body ImagingTomography, Emission-ComputedBrainGenetic LinkageLod ScoreRadiographic Image Interpretation, Computer-AssistedPhantoms, ImagingArtifactsImage Interpretation, Computer-AssistedTomography, Emission-Computed, Single-PhotonRadiographic Image EnhancementRadiation DosageAlgorithmsRadiography, AbdominalImage Enhancement