2013
Simultaneous 99mTc‐MDP/123I‐MIBG tumor imaging using SPECT‐CT: Phantom and constructed patient studies
Rakvongthai Y, Fakhri G, Lim R, Bonab A, Ouyang J. Simultaneous 99mTc‐MDP/123I‐MIBG tumor imaging using SPECT‐CT: Phantom and constructed patient studies. Medical Physics 2013, 40: 102506. PMID: 24089927, PMCID: PMC3785531, DOI: 10.1118/1.4820977.Peer-Reviewed Original ResearchConceptsScatter correctionDual-radionuclideContrast recoveryPhantom studyAnthropomorphic torso phantomPatient studiesTumor uptakeTumor imagingSPECT projectionsTorso phantomMonte-CarloPhantom dataPhantomIterative reconstructionOSEMProjection dataDR dataIncrease patient throughputNoise realizationsSPECT-CTImage reconstructionClinical studiesTumorTumor projectionPoisson noise
2010
Novel Scatter Compensation of List-Mode PET Data Using Spatial and Energy Dependent Corrections
Guérin B, Fakhri G. Novel Scatter Compensation of List-Mode PET Data Using Spatial and Energy Dependent Corrections. IEEE Transactions On Medical Imaging 2010, 30: 759-773. PMID: 21118770, PMCID: PMC3120772, DOI: 10.1109/tmi.2010.2095025.Peer-Reviewed Original ResearchConceptsScattered coincidencesEnergy resolutionE-pdfNCAT phantomDependent correctionsEnergy of individual photonsScatter correctionEnergy dependent correctionsEnergy probability density functionScatter correction schemeTotal energy spectrumList-mode acquisitionEnergy informationPositron emission tomography dataActivity distribution estimationScatter sinogramIndividual photonsEnergy spectrumCylindrical phantomEnergy distributionMonte Carlo simulationsScattering approachPhotonsScatteringScattering component
2009
Quantitative simultaneous cardiac SPECT using MC‐JOSEM
Ouyang J, Zhu X, Trott C, Fakhri G. Quantitative simultaneous cardiac SPECT using MC‐JOSEM. Medical Physics 2009, 36: 602-611. PMID: 19292000, PMCID: PMC2673670, DOI: 10.1118/1.3063544.Peer-Reviewed Original ResearchConceptsMC-JOSEMEnergy windowWater-filled torso phantomScatter correctionPhotopeak energy windowStandard OSEMCardiac SPECT imagingActivity concentration ratioIterative reconstruction algorithmReconstruction algorithmMyocardium wallTorso phantomActivity estimationDetector responseEmission energyBackground compartmentPhantom dataCardiac SPECTActivity distributionRest/stress imagingScatteringCases of patientsOSEMChest painCardiac protocols
2003
The Effects of Compensation for Scatter, Lead X-Rays, and High-Energy Contamination on Tumor Detectability and Activity Estimation in Ga-67 Imaging
Fakhri G, Kijewski M, Maksud P, Moore S. The Effects of Compensation for Scatter, Lead X-Rays, and High-Energy Contamination on Tumor Detectability and Activity Estimation in Ga-67 Imaging. IEEE Transactions On Nuclear Science 2003, 50: 439. DOI: 10.1109/tns.2003.812446.Peer-Reviewed Original ResearchLead X-raysHigh-energy contaminationPresence of scatteringOptimal energy windowSignal-to-noise ratioAnthropomorphic torso phantomHigh-energy photonsMonte Carlo programGa-67 imagingSpherical tumorCompton scatteringPhoton interactionsEnergy windowScattered photonsEnergy photonsPhotopeak windowTorso phantomActivity estimationHigh energyFactors affecting image qualityX-rayScatter correctionPhotopeakGa-67PhotonsEvaluation of a Monte Carlo Scatter Correction in Clinical 3D PET
Holdsworth C, Badawi R, Santos P, Van den Abbeele A, Hoffman E, Fakhri G. Evaluation of a Monte Carlo Scatter Correction in Clinical 3D PET. 2003, 4: 2540-2544. DOI: 10.1109/nssmic.2003.1352408.Peer-Reviewed Original ResearchScatter correctionUncorrected imagesPET imagingChannelized Hotelling observerHotelling observerPatient dataPatient imagesQuantitative accuracyLesion detection sensitivityPatient sizePhantomLesion sensitivityPatientsMonteLesionsLesion detectionCorrectionROI analysisIntensity varianceDetection sensitivityPETScatteringAverage absolute bias
2002
Quantitative Simultaneous 99MTc/123I Spect: Design Study and Validation With Monte Carlo Simulations and Physical Acquisitions
Fakhri G, Maksud P, Kijewski M, Zimmerman R, Moore S. Quantitative Simultaneous 99MTc/123I Spect: Design Study and Validation With Monte Carlo Simulations and Physical Acquisitions. IEEE Transactions On Nuclear Science 2002, 49: 2315. DOI: 10.1109/tns.2002.803819.Peer-Reviewed Original ResearchMonte Carlo simulationsBrain phantomCarlo simulationsSimultaneous dual-isotope imagingIterative ordered subsetsDigital brain phantomDual-isotope SPECT studyVariable collimator responseArtificial neural networkPhysical acquisitionEnergy windowNonuniform attenuationCollimator responseDual-isotope imagingPhantom acquisitionsScatter correctionClinical cameraNeural networkMontePhantomIsotope imagingCorrected projectionsSPECT studiesProjector/backprojectorClinical application
2001
A New Scatter Compensation Method for Ga-67 Imaging Using Artificial Neural Networks
Fakhri G, Moore S, Maksud P. A New Scatter Compensation Method for Ga-67 Imaging Using Artificial Neural Networks. IEEE Transactions On Nuclear Science 2001, 48: 799. DOI: 10.1109/23.940166.Peer-Reviewed Original ResearchK-shell X-raysEnergy window imagesAnthropomorphic torso phantomPoisson noise realizationsGa-67 studiesArtificial neural networkWindow imagesPhotoelectric absorptionPhoton interactionsTorso phantomCoherent scatteringMonte Carlo simulationsScatter correctionGa-67Neural networkReconstructed volumeCarlo simulationsCollimatorArtificial neural network learningError back propagationNoise realizationsScatteringGa-67 imagingActivity estimationOutput layerAbsolute Quantitation in Simultaneous 99mTc/123I Brain SPECT Using ANN: Design Optimization and Validation
Fakhri G, Maksud P, Moore S, Zimmerman R, Kijewski M. Absolute Quantitation in Simultaneous 99mTc/123I Brain SPECT Using ANN: Design Optimization and Validation. 2001, 3: 1429-1431. DOI: 10.1109/nssmic.2001.1008605.Peer-Reviewed Original ResearchMonte Carlo simulationsBrain phantomSimultaneous dual-isotope imagingDigital brain phantomDual-isotope SPECT studyVariable collimator responseCarlo simulationsNon-uniform attenuationI-123 imagingEnergy windowCollimator responseDual-isotope imagingPhantom acquisitionsOSEM algorithmArtificial neural networkPhysical acquisitionScatter correctionClinical cameraBrain structuresPhantomIsotope imagingMonteSPECT studiesActivity concentrationsTc-99
2000
Relative impact of scatter, collimator response, attenuation, and finite spatial resolution corrections in cardiac SPECT.
El Fakhri G, Buvat I, Benali H, Todd-Pokropek A, Di Paola R. Relative impact of scatter, collimator response, attenuation, and finite spatial resolution corrections in cardiac SPECT. Journal Of Nuclear Medicine 2000, 41: 1400-8. PMID: 10945534.Peer-Reviewed Original ResearchConceptsDepth-dependent collimator responseSpatial resolution correctionCollimator responseFinite spatial resolutionBull's-eye mapCardiac SPECTActivity quantitationAttenuation correctionScatter correctionResolution correctionSpatial resolutionCollimator response correctionsSignal-to-noise ratioFrequency-distance principleImpact of scatteringLeft ventricleMonte Carlo simulationsCardiac phantomScatteringCarlo simulationsLV cavityAbsolute quantitationImproved contrastLV regionsProcessing schemeA new scatter compensation method for Ga-67 imaging using artificial neural networks
Fakhri G, Moore S, Maksud P. A new scatter compensation method for Ga-67 imaging using artificial neural networks. 2011 IEEE Nuclear Science Symposium Conference Record 2000, 2: 13/48-13/52 vol.2. DOI: 10.1109/nssmic.2000.949989.Peer-Reviewed Original ResearchK-shell X-raysEnergy window imagesAnthropomorphic torso phantomScatter correction methodPoisson noise realizationsGa-67 studiesPhotoelectric absorptionPhoton interactionsWindow imagesTorso phantomArtificial neural networkCoherent scatteringMonte Carlo simulationsScatter correctionGa-67Reconstructed volumeNeural networkCarlo simulationsCollimatorNoise realizationsScatteringGa-67 imagingArtificial neural network learningPrimary distributionError backpropagation
1998
Artificial neural network as a tool to compensate for scatter and attenuation in radionuclide imaging.
Maksud P, Fertil B, Rica C, El Fakhri G, Aurengo A. Artificial neural network as a tool to compensate for scatter and attenuation in radionuclide imaging. Journal Of Nuclear Medicine 1998, 39: 735-45. PMID: 9544691.Peer-Reviewed Original ResearchConceptsEnergy spectrumCompton scatteringRadioactive sourcesImages of radioactive sourcesScatter correctionArtificial neural networkNeural networkNumerical Monte Carlo simulationsMonte Carlo simulationsPelvis scansIncident photonsMultilayer neural networkProjection imagesScatteringComptonCarlo simulationsDiffusion mediaSource distributionSpectrum acquisitionEnergyGeometric sourcesHomogeneous mediumCorrectionSpectraNetwork