2021
Quantitative PET in the 2020s: a roadmap
Meikle S, Sossi V, Roncali E, Cherry S, Banati R, Mankoff D, Jones T, James M, Sutcliffe J, Ouyang J, Petibon Y, Ma C, El Fakhri G, Surti S, Karp J, Badawi R, Yamaya T, Akamatsu G, Schramm G, Rezaei A, Nuyts J, Fulton R, Kyme A, Lois C, Sari H, Price J, Boellaard R, Jeraj R, Bailey D, Eslick E, Willowson K, Dutta J. Quantitative PET in the 2020s: a roadmap. Physics In Medicine And Biology 2021, 66: 06rm01. PMID: 33339012, PMCID: PMC9358699, DOI: 10.1088/1361-6560/abd4f7.Peer-Reviewed Original ResearchMeSH KeywordsArtificial IntelligenceHistory, 20th CenturyHistory, 21st CenturyHumansImage Processing, Computer-AssistedImaging, Three-DimensionalKineticsMedical OncologyNeoplasmsPositron Emission Tomography Computed TomographyPositron-Emission TomographyPrognosisRadiopharmaceuticalsSystems BiologyTomography, X-Ray ComputedConceptsTime-of-flight positron emission tomographyStatistical image reconstructionTotal-body positron emission tomographyPositron emission tomographyQuantitative positron emission tomographyImage reconstructionWhole-body positron emission tomographySensitivity of positron emission tomographyCapabilities of positron emission tomographyImage qualityClinical applicationTracer principleRelevant parametersOncology applicationsPhysicsStatistical qualityExpansion of applicationsEmission tomographyClinical practicePET/MRBiologically relevant parametersSensitive biomarkerPositron
2020
Attenuation correction using deep Learning and integrated UTE/multi-echo Dixon sequence: evaluation in amyloid and tau PET imaging
Gong K, Han P, Johnson K, El Fakhri G, Ma C, Li Q. Attenuation correction using deep Learning and integrated UTE/multi-echo Dixon sequence: evaluation in amyloid and tau PET imaging. European Journal Of Nuclear Medicine And Molecular Imaging 2020, 48: 1351-1361. PMID: 33108475, PMCID: PMC8411350, DOI: 10.1007/s00259-020-05061-w.Peer-Reviewed Original ResearchMeSH KeywordsDeep LearningHumansImage Processing, Computer-AssistedMagnetic Resonance ImagingMultimodal ImagingPositron-Emission TomographyTomography, X-Ray ComputedConceptsAttenuation correctionResultsThe Dice coefficientPseudo-CT imagesMR-based AC methodsAccurate ACAC accuracyPET imagingDice coefficientQuantitative accuracyAtlas methodAC methodGradient echoNear verticesTau imagingTau PET imagingAlzheimer's diseaseUltrashortCorrectionTau pathologyRapid acquisitionDeep learning methodsMonitoring of Alzheimer’s diseasePET/MRAmyloidIn vivo quantitative mapping of human mitochondrial cardiac membrane potential: a feasibility study
Pelletier-Galarneau M, Petibon Y, Ma C, Han P, Kim S, Detmer F, Yokell D, Guehl N, Normandin M, El Fakhri G, Alpert N. In vivo quantitative mapping of human mitochondrial cardiac membrane potential: a feasibility study. European Journal Of Nuclear Medicine And Molecular Imaging 2020, 48: 414-420. PMID: 32719915, PMCID: PMC7839097, DOI: 10.1007/s00259-020-04878-9.Peer-Reviewed Original ResearchMeSH KeywordsFeasibility StudiesHumansMembrane PotentialsMyocardiumPositron-Emission TomographyTomography, X-Ray ComputedConceptsMembrane potentialBolus injectionHealthy subjectsHematocrit levelsSerial venous blood samplesT1 mapping imagesVenous blood samplesExtracellular space fractionMethodsThirteen healthy subjectsDynamic PET acquisitionCellular membrane potentialGadolinium injectionPrognostic informationVentricular arrhythmiasHeart failureMyocardial hypertrophyMitochondrial membrane potentialCardiac diseaseIn vitro assessmentTherapy monitoringBlood concentrationsPET acquisitionImaging protocolBlood samplesPlasma tracer concentrationMR‐based PET attenuation correction using a combined ultrashort echo time/multi‐echo Dixon acquisition
Han P, Horng D, Gong K, Petibon Y, Kim K, Li Q, Johnson K, Fakhri G, Ouyang J, Ma C. MR‐based PET attenuation correction using a combined ultrashort echo time/multi‐echo Dixon acquisition. Medical Physics 2020, 47: 3064-3077. PMID: 32279317, PMCID: PMC7375929, DOI: 10.1002/mp.14180.Peer-Reviewed Original ResearchMeSH KeywordsHumansImage Processing, Computer-AssistedMagnetic Resonance ImagingPhantoms, ImagingPositron-Emission TomographyTomography, X-Ray ComputedConceptsLinear attenuation coefficientPositron emission tomography attenuation correctionPhysical compartmental modelAttenuation correctionShort T<sub>2</sub> componentPET attenuation correctionRadial k-space trajectoryMagnetic resonance (MR)-based methodK-space trajectoriesRadial trajectoryK-spaceAttenuation coefficientDixon acquisitionsPositron emission tomographyWhole white matterMuting methodImage reconstructionImaging speedMR signalMRAC methodPositron emission tomography imagingCorrectionGray matter regionsPhantomMatter regions
2019
Exploring light confinement in laser-processed LYSO:Ce for photon counting CT application
Bläckberg L, Sajedi S, Mandl S, Mohan A, Vittum B, Fakhri G, Sabet H. Exploring light confinement in laser-processed LYSO:Ce for photon counting CT application. Physics In Medicine And Biology 2019, 64: 095020. PMID: 30897557, PMCID: PMC7191943, DOI: 10.1088/1361-6560/ab1213.Peer-Reviewed Original ResearchConceptsLaser induced optical barriersPhoton counting detectorsLight collection efficiencyCrystal pixelsLYSO:Ce detectorsHigh dose efficiencyPixel arrayCounting detectorsDetector designDose efficiencyOptical barrierPd edgePhotodetector (PDRough interfaceIncreased cross-talkCE detectorCT applicationsDetectorLaser ablationPixel sizeConfinementSmooth ablationLYSOSpatial resolutionCollection efficiency
2018
Advances in coronary molecular imaging: Leveraging the power of image processing
Abdelbaky A, El Fakhri G, Tawakol A. Advances in coronary molecular imaging: Leveraging the power of image processing. Journal Of Nuclear Cardiology 2018, 27: 505-507. PMID: 30367381, PMCID: PMC6486447, DOI: 10.1007/s12350-018-1454-x.Peer-Reviewed Original ResearchHeartImage Processing, Computer-AssistedPositron Emission Tomography Computed TomographyTomography, X-Ray Computed
2017
Low‐dose CT reconstruction using spatially encoded nonlocal penalty
Kim K, Fakhri G, Li Q. Low‐dose CT reconstruction using spatially encoded nonlocal penalty. Medical Physics 2017, 44: e376-e390. PMID: 29027240, PMCID: PMC5927365, DOI: 10.1002/mp.12523.Peer-Reviewed Original ResearchMeSH KeywordsHumansImage Processing, Computer-AssistedQuality ControlRadiation DosageTomography, X-Ray ComputedConceptsLow Dose CT Grand ChallengeDose imagesDose dataFlying focal spotQuadratic surrogatesLow-dose CT reconstructionCT reconstruction methodImage qualityRadiation doseCT phantomFBP imagesRaw projectionsRebinning methodFocal spotLog-likelihoodReconstructed test imagesEfficient memory usageNesterov's momentum methodPoisson log-likelihoodGrand ChallengeComputed tomographyLow radiation doseCT reconstructionAccurate diagnostic featuresTest imagesIterative Low-Dose CT Reconstruction With Priors Trained by Artificial Neural Network
Wu D, Kim K, Fakhri G, Li Q. Iterative Low-Dose CT Reconstruction With Priors Trained by Artificial Neural Network. IEEE Transactions On Medical Imaging 2017, 36: 2479-2486. PMID: 28922116, PMCID: PMC5897914, DOI: 10.1109/tmi.2017.2753138.Peer-Reviewed Original ResearchMeSH KeywordsAbdomenAlgorithmsHumansNeural Networks, ComputerRadiation DosageRadiographic Image Interpretation, Computer-AssistedThoraxTomography, X-Ray ComputedConceptsArtificial neural networkIterative reconstruction algorithmNeural networkLow-dose CT reconstructionReconstruction algorithmUnsupervised feature learningReconstructed imagesFeatures of imagesImprove reconstruction qualityNormal-dose imagesDecreasing radiation riskDevelopment of artificial neural networksFeature learningComplex featuresAuto-encoderReconstruction qualityData fidelityMachine learningSuppress noiseSmoothness constraintPhoton fluxPreservation abilityGrand ChallengeNoise reductionPriorsMagnetic Resonance–based Motion Correction for Quantitative PET in Simultaneous PET-MR Imaging
Rakvongthai Y, Fakhri G. Magnetic Resonance–based Motion Correction for Quantitative PET in Simultaneous PET-MR Imaging. PET Clinics 2017, 12: 321-327. PMID: 28576170, PMCID: PMC6452624, DOI: 10.1016/j.cpet.2017.02.004.Peer-Reviewed Original ResearchConceptsSimultaneous PET-MRQuantitative PET imagingMotion correctionSimultaneous PET-MR imagingReconstructed PET imagesMotion-corrected imagesPET-MRMotion correction strategiesPET imagingPET-MR imagingQuantitation of PET imagesPatient studiesQuantitative PETImage qualityMotionCorrectionPhantomAnatomical informationCorrection strategyMR imaging
2015
Mapping 15O Production Rate for Proton Therapy Verification
Grogg K, Alpert N, Zhu X, Min C, Testa M, Winey B, Normandin M, Shih H, Paganetti H, Bortfeld T, Fakhri G. Mapping 15O Production Rate for Proton Therapy Verification. International Journal Of Radiation Oncology • Biology • Physics 2015, 92: 453-459. PMID: 25817530, PMCID: PMC4431894, DOI: 10.1016/j.ijrobp.2015.01.023.Peer-Reviewed Original ResearchConceptsDecay constantProton treatment planningMonte Carlo predictionsProton therapyPhantom materialTreatment deliveryPhantomThigh activityPositron emission tomographyProduction rateDynamic PET measurementsTreatment planningRabbit thigh muscleClearance rateProtonIsotopesChanges due to therapyRadionuclide speciesOxygen-15ConstantDecayImaging targetsMontePositronEffects of perfusion
2014
Sparse-View Spectral CT Reconstruction Using Spectral Patch-Based Low-Rank Penalty
Kim K, Ye J, Worstell W, Ouyang J, Rakvongthai Y, Fakhri G, Li Q. Sparse-View Spectral CT Reconstruction Using Spectral Patch-Based Low-Rank Penalty. IEEE Transactions On Medical Imaging 2014, 34: 748-760. PMID: 25532170, DOI: 10.1109/tmi.2014.2380993.Peer-Reviewed Original ResearchMeSH KeywordsAlgorithmsAtherosclerosisComputer SimulationHumansPhantoms, ImagingPoisson DistributionSpectrometry, X-Ray EmissionTomography, X-Ray ComputedConceptsLow-rank penaltySelf-similarity of patchesLog-likelihoodPoisson log-likelihoodCost functionSpectral CT reconstructionOriginal cost functionGPU implementationAlternating minimizationSensitive to intensity changesConventional algorithmsSpectral imagingEdge directionComputational costProcedure algorithmComputational advantagesAlgorithmX-ray transmissionComputer simulationsOptimization methodSpectral computed tomographySelf-similarityCT reconstructionX-rayGPUSpectral CT Using Multiple Balanced K-Edge Filters
Rakvongthai Y, Worstell W, Fakhri G, Bian J, Lorsakul A, Ouyang J. Spectral CT Using Multiple Balanced K-Edge Filters. IEEE Transactions On Medical Imaging 2014, 34: 740-747. PMID: 25252276, PMCID: PMC4349342, DOI: 10.1109/tmi.2014.2358561.Peer-Reviewed Original ResearchMeSH KeywordsComputer SimulationFiltrationHumansPhantoms, ImagingRadiographic Image Interpretation, Computer-AssistedSpectrometry, X-Ray EmissionTomography, X-Ray ComputedConceptsK-edge filtersReconstructed attenuation coefficientsEnergy binsAttenuation coefficientMultiple energy binsX-ray sourcesX-ray tubeBack-projection reconstructionSpectral CT imagingTransmission matrixModel expectationsSinogram binsBeam hardeningComplex phantomsSpectral computed tomographyK-edgeAttenuation imagesSpectral CTCT scannerX-rayConventional detectorsBack-projectionSinogramPhantomCost-effective system design
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
2009
Quantitative relationship between coronary calcium content and coronary flow reserve as assessed by integrated PET/CT imaging
Curillova Z, Yaman B, Dorbala S, Kwong R, Sitek A, El Fakhri G, Anagnostopoulos C, Di Carli M. Quantitative relationship between coronary calcium content and coronary flow reserve as assessed by integrated PET/CT imaging. European Journal Of Nuclear Medicine And Molecular Imaging 2009, 36: 1603-1610. PMID: 19387640, PMCID: PMC3117296, DOI: 10.1007/s00259-009-1121-1.Peer-Reviewed Original ResearchConceptsCoronary artery calcium scoreCoronary artery calciumCoronary vasodilator functionCoronary flow reserveCoronary artery diseaseHyperemic myocardial blood flowMyocardial blood flowVasodilator functionWeak inverse correlationCAC scoreCoronary artery calcium contentFlow reserveIncreasing CAC scorePer-vessel basisPer-patient basisInverse correlationBody mass indexCoronary calcium contentCoronary risk factorsCoronary vascular resistancePET/CT imagingConclusionIn patientsArtery calciumVascular resistanceMass indexQuantitative 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
2007
Clinical Myocardial Perfusion PET/CT
Di Carli M, Dorbala S, Meserve J, Fakhri G, Sitek A, Moore S. Clinical Myocardial Perfusion PET/CT. Journal Of Nuclear Medicine 2007, 48: 783-793. PMID: 17475968, DOI: 10.2967/jnumed.106.032789.Peer-Reviewed Original ResearchMeSH KeywordsCoronary Artery DiseaseHumansImage EnhancementPositron-Emission TomographySubtraction TechniqueTomography, X-Ray ComputedVentricular Dysfunction, LeftConceptsCoronary artery diseaseMyocardial perfusion PETPerfusion PETDiagnosing obstructive CADClinically useful risk stratificationObstructive coronary artery diseaseAnatomic coronary artery diseaseMyocardial perfusion PET/CTMultivessel coronary artery diseaseLeft ventricular functionEvaluation of patientsQuantify myocardial perfusionVentricular functionIschemic burdenPharmacological stressRisk stratificationCardiac PETArtery diseasePET/CT technologyMyocardial perfusionAttenuation correctionNuclear cardiologyFunctional consequencesSPECTPET