2022
Posterior estimation using deep learning: a simulation study of compartmental modeling in dynamic positron emission tomography
Liu X, Marin T, Amal T, Woo J, Fakhri G, Ouyang J. Posterior estimation using deep learning: a simulation study of compartmental modeling in dynamic positron emission tomography. Medical Physics 2022, 50: 1539-1548. PMID: 36331429, PMCID: PMC10087283, DOI: 10.1002/mp.16078.Peer-Reviewed Original ResearchMeSH KeywordsBayes TheoremComputer SimulationDeep LearningNeural Networks, ComputerPositron-Emission TomographyConceptsConditional variational auto-encoderDeep learning approachNeural networkDeep learningMarkov chain Monte CarloVariational Bayesian inference frameworkLearning approachDeep learning-based approachVariational auto-encoderDeep neural networksLearning-based approachDynamic brain PET imagingPosterior distributionEstimate posterior distributionsBayesian inference frameworkAuto-encoderMedical imagesInference frameworkNetworkSimulation studyBrain PET imagingLearningPosterior estimatesInferior performanceImages
2020
PET imaging of neurotransmission using direct parametric reconstruction
Petibon Y, Alpert N, Ouyang J, Pizzagalli D, Cusin C, Fava M, Fakhri G, Normandin M. PET imaging of neurotransmission using direct parametric reconstruction. NeuroImage 2020, 221: 117154. PMID: 32679252, PMCID: PMC7800040, DOI: 10.1016/j.neuroimage.2020.117154.Peer-Reviewed Original ResearchMeSH KeywordsBrainComputer SimulationHumansNeuroimagingPositron-Emission TomographyRadiopharmaceuticalsSynaptic TransmissionConceptsSignal-to-noise ratioImage reconstructionPositron emission tomography image reconstructionLow signal-to-noise ratioPoisson log-likelihood functionScattered coincidencesDetector sensitivityPET sinogramsStatistical fluctuationsEstimate parametric imagesGradient-based optimizationParametric reconstructionLog-likelihood functionEffects of head movementVoxel scalePositron emission tomographySimplified reference region modelActivity concentration data
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-rayGPU4D numerical observer for lesion detection in respiratory‐gated PET
Lorsakul A, Li Q, Trott C, Hoog C, Petibon Y, Ouyang J, Laine A, Fakhri G. 4D numerical observer for lesion detection in respiratory‐gated PET. Medical Physics 2014, 41: 102504. PMID: 25281979, PMCID: PMC4281099, DOI: 10.1118/1.4895975.Peer-Reviewed Original ResearchMeSH KeywordsAlgorithmsComputer SimulationFluorodeoxyglucose F18HumansImage Interpretation, Computer-AssistedLung DiseasesModels, BiologicalMonte Carlo MethodMotionPhantoms, ImagingPositron-Emission TomographyRadiopharmaceuticalsRegression AnalysisRespiratory-Gated Imaging TechniquesSignal-To-Noise RatioConceptsRespiratory-gated positron emission tomographyMotion-corrected imagesDetection signal-to-noise ratioLesion detection taskNumerical observationsLesion detection performanceSignal-to-noise ratioPositron emission tomography sinogramsSpherical lesionsHotelling observerMotion correction methodPositron emission tomographyGeant4 ApplicationTomographic EmissionChannelized Hotelling observerAnthropomorphic phantomScanner geometryOSEM algorithmMonte Carlo simulationsPET framesImprove lesion detectionLesion detectionSignal-to-noise ratio measurementsActivity distributionConventional 3D approachSpectral 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 ResearchConceptsK-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 designEffect of time‐of‐flight and point spread function modeling on detectability of myocardial defects in PET
Schaefferkoetter J, Ouyang J, Rakvongthai Y, Nappi C, El Fakhri G. Effect of time‐of‐flight and point spread function modeling on detectability of myocardial defects in PET. Medical Physics 2014, 41: 062502. PMID: 24877836, PMCID: PMC4032408, DOI: 10.1118/1.4875725.Peer-Reviewed Original ResearchConceptsSignal-to-noise ratioDetection signal-to-noise ratioPoint spread functionObserver signal-to-noise ratioEffects of time-of-flightMyocardial defectsHuman observer performanceDefect detectionSlow convergenceTime-of-flight (TOFNon-PSFPostreconstruction smoothingFDG-PET dataTime-of-flightPSF reconstructionCombination of TOFNon-TOFIterationObserver performanceClinical practiceSpread functionReconstruction parametersReconstruction protocolsIterative methodDetectionTowards coronary plaque imaging using simultaneous PET-MR: a simulation study
Petibon Y, Fakhri G, Nezafat R, Johnson N, Brady T, Ouyang J. Towards coronary plaque imaging using simultaneous PET-MR: a simulation study. Physics In Medicine And Biology 2014, 59: 1203-1222. PMID: 24556608, PMCID: PMC4061607, DOI: 10.1088/0031-9155/59/5/1203.Peer-Reviewed Original ResearchMeSH KeywordsComputer SimulationCoronary AngiographyCoronary StenosisHumansImage Interpretation, Computer-AssistedImaging, Three-DimensionalMagnetic Resonance AngiographyModels, CardiovascularMultimodal ImagingPhantoms, ImagingPositron-Emission TomographyReproducibility of ResultsSensitivity and SpecificityConceptsSimultaneous PET-MRChannelized Hotelling observerAttenuation mapMotion correctionPET-MRFluorodeoxyglucose-positron emission tomography imagingRespiratory motion fieldsMotion correction methodCho SNRMotion correction techniqueAnthropomorphic phantomUncorrected reconstructionsRespiratory motionXCAT phantomCoronary plaque imagingMonte Carlo simulationsPET reconstructionXCATActivity distributionCardiac gatingNon-rigid registrationHotelling observerCarlo simulationsPlaque imagingPhantom