2023
PET image denoising based on denoising diffusion probabilistic model
Gong K, Johnson K, El Fakhri G, Li Q, Pan T. PET image denoising based on denoising diffusion probabilistic model. European Journal Of Nuclear Medicine And Molecular Imaging 2023, 51: 358-368. PMID: 37787849, PMCID: PMC10958486, DOI: 10.1007/s00259-023-06417-8.Peer-Reviewed Original ResearchMeSH KeywordsAlgorithmsHumansImage Processing, Computer-AssistedModels, StatisticalPositron-Emission TomographySignal-To-Noise RatioConceptsDenoising diffusion probabilistic modelPET image denoisingDiffusion probabilistic modelImage denoisingDenoising methodNonlocal meansNetwork inputGenerative adversarial networkData consistency constraintsProbabilistic modelLearning-based modelsAdversarial networkData distributionDenoisingRefinement stepsIterative refinementFlexible frameworkImage qualityPhysical degrading factorsUNetNetworkDatasetImagesInputNoise level
2015
Stochastic simulation of radium-223 dichloride therapy at the sub-cellular level
Gholami Y, Zhu X, Fulton R, Meikle S, El-Fakhri G, Kuncic Z. Stochastic simulation of radium-223 dichloride therapy at the sub-cellular level. Physics In Medicine And Biology 2015, 60: 6087-6096. PMID: 26216391, DOI: 10.1088/0031-9155/60/15/6087.Peer-Reviewed Original ResearchMeSH KeywordsAlpha ParticlesCell NucleusDNA DamageHumansMaleModels, StatisticalMonte Carlo MethodRadioisotopesRadiopharmaceuticalsRadiumConceptsEstimate radiation damageAlpha particle tracksAlpha-particle emittersMonte Carlo modelIonization clustersDose depositionAlpha particlesAlpha emissionParticle therapyAlpha-particle therapyEnergy depositionRadiation damageCarlo modelEfficacy of cell killingParticle emittersRadium-223 dichlorideBone-seeking radionuclidesParticle trackingRadium-223Prostate cancerAverage doseCell nucleiCell killingIndirect DNA damageNucleus
2009
Monte Carlo modeling of cascade gamma rays in 86Y PET imaging: preliminary results
Zhu X, Fakhri G. Monte Carlo modeling of cascade gamma rays in 86Y PET imaging: preliminary results. Physics In Medicine And Biology 2009, 54: 4181-4193. PMID: 19521011, PMCID: PMC3111055, DOI: 10.1088/0031-9155/54/13/014.Peer-Reviewed Original ResearchConceptsCascade gamma raysScatter fractionGamma raysPhoton energy distributionLow count ratesHigh-energy photonsMonte Carlo programScatter correction methodGATE simulation packageMonte Carlo modelDevelopment of correction methodsSpatial resolutionGamma photonsEnergy windowCount rateScattering eventsRandom coincidencesEnergy distributionPhantom acquisitionsPersonal dosimetryPET imagingVariance reduction techniquesPhotonsCorrection methodSimSET
2008
Sequential and simultaneous dual‐isotope brain SPECT: Comparison with PET for estimation and discrimination tasks in early Parkinson disease
Trott C, Fakhri G. Sequential and simultaneous dual‐isotope brain SPECT: Comparison with PET for estimation and discrimination tasks in early Parkinson disease. Medical Physics 2008, 35: 3343-3353. PMID: 18697558, PMCID: PMC2673561, DOI: 10.1118/1.2940605.Peer-Reviewed Original ResearchConceptsEnergy resolutionTime-of-flight PET scannerRealistic Monte Carlo simulationsAcquisition energy windowSequential SPECTSystem energy resolutionGamma cameraEnergy windowThree-head cameraPET scannerEmission energyMonte Carlo simulationsDual-isotope SPECTSimultaneous SPECTBrain PETTwo-headed cameraCarlo simulationsProdromal disease stagesIdentical physiological conditionsSpatial resolutionDiscrimination taskStriatal sizeActivity concentrationsEarly identification of PDCamera headImproved activity estimation with MC‐JOSEM versus TEW‐JOSEM in SPECT
Ouyang J, Fakhri G, Moore S. Improved activity estimation with MC‐JOSEM versus TEW‐JOSEM in SPECT. Medical Physics 2008, 35: 2029-2040. PMID: 18561679, PMCID: PMC2673642, DOI: 10.1118/1.2907561.Peer-Reviewed Original ResearchMeSH KeywordsAlgorithmsEquipment DesignImage Processing, Computer-AssistedIndium RadioisotopesLungModels, StatisticalMonte Carlo MethodPhantoms, ImagingRadiotherapy Planning, Computer-AssistedReproducibility of ResultsScattering, RadiationSoftwareTomography, Emission-Computed, Single-PhotonTomography, X-Ray ComputedConceptsMC-JOSEMWater-filled torso phantomMC scatter estimationTriple-energy-windowActivity estimationIterative reconstruction algorithmTorso phantomPhantom studyBackground compartmentScatter estimationActivity distributionAverage relative biasPhantomReconstruction algorithmActivity concentrationsSynthetic projectionsSphere locationScattering
1998
Two-dimensional statistical model for regularized backprojection in SPECT
Pélégrini M, Benali H, Buvat I, Fakhri G, Di Paola R. Two-dimensional statistical model for regularized backprojection in SPECT. Physics In Medicine And Biology 1998, 43: 421-434. PMID: 9509536, DOI: 10.1088/0031-9155/43/2/015.Peer-Reviewed Original Research