2019
Limited-Angle TOF-PET for Intraoperative Surgical Application
Sajedi S, Bläckberg L, Vittum B, Devabhaktuni A, Nejad M, Fakhri G, Choi H, Sabet H. Limited-Angle TOF-PET for Intraoperative Surgical Application. 2019, 00: 1-4. DOI: 10.1109/nss/mic42101.2019.9059690.Peer-Reviewed Original ResearchSentinel lymph nodeHigh-resolution positron emission tomographyTOF-PETNear-infraredDetector ringDetector blockIncreasing acquisition timeTorso phantomHot spheresBottom detectorPositron emission tomographyTime resolutionDetectorIdentification of sentinel lymph nodesAcquisition timeSentinel lymph node identificationReconstructed imagesAccurate identification of sentinel lymph nodesActivity concentrationsWhole-body positron emission tomographyComplete tumor removalFalse negative rateImage slicesImprove patient recoveryPatient bed
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 noiseSpatially varying regularization for motion compensated PET reconstruction
Dutta J, Fakhri G, Lin Y, Huang C, Petibon Y, Reese T, Leahy R, Li Q. Spatially varying regularization for motion compensated PET reconstruction. 2011 IEEE Nuclear Science Symposium Conference Record 2013, 2156-2160. DOI: 10.1109/nssmic.2012.6551493.Peer-Reviewed Original ResearchSimulated lung lesionsRegularization schemeSpatially varying regularizationUngated reconstructionTorso phantomImage reconstruction problemContrast recoverySacrificing signal-to-noise ratioPET reconstructionSignal-to-noise ratioAnalytical approximationReconstruction frameworkQuadratic penaltyDiagonal elementsReconstruction problemLocal impulse responseCardiac motionRegularization approachReconstructed imagesFisher information matrixAutomated fashionPET imagingImpulse responseDegree of smoothnessInformation matrix
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
2008
Improved 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
2006
Monte Carlo-based compensation for patient scatter, detector scatter, and crosstalk contamination in In-111 SPECT imaging
Moore S, Ouyang J, Park M, Fakhri G. Monte Carlo-based compensation for patient scatter, detector scatter, and crosstalk contamination in In-111 SPECT imaging. Nuclear Instruments And Methods In Physics Research Section A Accelerators Spectrometers Detectors And Associated Equipment 2006, 569: 472-476. DOI: 10.1016/j.nima.2006.08.079.Peer-Reviewed Original ResearchScatter projectionsPatient scatterDetector scatterOrgan activity estimatesPhoton interaction pointIterative reconstruction algorithmDetector effectsEnergy binsReconstruction algorithmDelta scatteringTorso phantomPoint spread functionSegmented CT scanInteraction pointOSEM reconstructionNumerical phantomDetectorScatteringScattering mapSpherical tumorSpread functionImage noisePhantomActivity concentrationsActivity estimationMonte Carlo Modeling of Cascade Gamma Rays in PET
Zhu X, Fakhri G. Monte Carlo Modeling of Cascade Gamma Rays in PET. 2011 IEEE Nuclear Science Symposium Conference Record 2006, 6: 3522-3525. DOI: 10.1109/nssmic.2006.353759.Peer-Reviewed Original ResearchCascade gamma raysGamma raysGamma-ray emitting isotopesDetector dead timeMonte Carlo modelPET imagingGamma eventsScatter fractionQuantitative PET imagingTorso phantomSingles ratesMonte Carlo simulationsDecrease of intensityHigh-activity regionsPhantom experimentsReconstructed volumePhantomRaysCarlo simulationsDead timeDetectorReconstructed imagesCascade typeImage intensityMonte
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-67Photons
2002
Optimization of Ga‐67 imaging for detection and estimation tasks: Dependence of imaging performance on spectral acquisition parameters
Fakhri G, Moore S, Kijewski M. Optimization of Ga‐67 imaging for detection and estimation tasks: Dependence of imaging performance on spectral acquisition parameters. Medical Physics 2002, 29: 1859-1866. PMID: 12201433, DOI: 10.1118/1.1493214.Peer-Reviewed Original ResearchConceptsIdeal signal-to-noise ratioEnergy windowSignal-to-noise ratioMonte Carlo programDetection of spheresTorso phantomPhantom acquisitionsSphere of radiusEstimation taskPhantom dataLower-energyGa-67 imagingPhantomAcquisition parametersActivity concentrationsSpectral acquisition parametersGa-67Sphere sizeEnergyPhotopeakTumor imagingOptimal windowTaskClinicMonte
2001
Realistic Monte Carlo Simulation of Ga-67 SPECT Imaging
Moore S, El Fakhri G. Realistic Monte Carlo Simulation of Ga-67 SPECT Imaging. IEEE Transactions On Nuclear Science 2001, 48: 720. DOI: 10.1109/23.940153.Peer-Reviewed Original ResearchRealistic Monte Carlo simulationsNumerical torso phantomLead X-raysMonte Carlo programPhoton emission energyPoisson noise realizationsGa-67 SPECT imagingCollimator penetrationDetector resolutionEnergy windowRSD phantomPhoton propagationPhoton scatteringTorso phantomHeart/thorax phantomAttenuation mapEnergy distributionEmission energyImproved variance reductionSPECT imagesPhantomGa-67 studiesNoise realizationsScatteringAxillary lymph nodesA 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 layerOptimization of Ga-67 Imaging for Detection and Estimation Tasks: Dependence of Imaging Performance on Choice of Energy Windows
Fakhri G, Moore S, Kijewski M. Optimization of Ga-67 Imaging for Detection and Estimation Tasks: Dependence of Imaging Performance on Choice of Energy Windows. 2001, 3: 1355-1357. DOI: 10.1109/nssmic.2001.1008588.Peer-Reviewed Original ResearchEnergy windowSignal-to-noise ratioMonte Carlo programDetection of spheresIdeal signal-to-noise ratioTorso phantomEstimation taskDetection signal-to-noise ratioPhantom acquisitionsSphere of radiusPhantom dataLower-energyPhotopeakImaging performancePhantomGa-67Detection metricsGa-67 imagingSphere sizeOptimal window widthWindow widthEnergyTaskQuantitative tasksOptimal window
2000
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. 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 backpropagationRealistic Monte Carlo simulation of Ga-67 imaging for optimization and evaluation of correction methods
Moore S, Fakhri G. Realistic Monte Carlo simulation of Ga-67 imaging for optimization and evaluation of correction methods. 2011 IEEE Nuclear Science Symposium Conference Record 2000, 3: 20/35-20/38 vol.3. DOI: 10.1109/nssmic.2000.949312.Peer-Reviewed Original ResearchRealistic Monte Carlo simulationsNumerical torso phantomMonte Carlo programLead X-raysPhoton emission energyPoisson noise realizationsMaximum rectangular regionCollimator penetrationDetector resolutionEnergy windowRSD phantomPhoton scatteringPhoton propagationTorso phantomHeart/thorax phantomAttenuation mapEnergy distributionEmission energyImproved variance reductionPhantomNoise-free imageGa-67 studiesGa-67Noise realizationsScatteringRelative lesion detectability in 3D vs. 2D dedicated multi-ring PET
Moore S, Fakhri G, Badawi R, Van den Abbeele A, Zimmerman R. Relative lesion detectability in 3D vs. 2D dedicated multi-ring PET. 2011 IEEE Nuclear Science Symposium Conference Record 2000, 3: 17/18-17/22 vol.3. DOI: 10.1109/nssmic.2000.949192.Peer-Reviewed Original ResearchField of viewNon-prewhiteningAxial field-of-viewMaximum ring differenceAnthropomorphic torso phantomClinically realistic phantomDetection of spheresNPW-SNRTorso phantomGe-68Head phantomDetection signal-to-noise ratioRing differenceRealistic phantomsPhantomBed positionF-18Signal-to-noise ratioActivity concentrationsTwo-dimensionalContrast levelsPET imagingCompare two-dimensionalModeFORE+FBP