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 ResearchConceptsSignal-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
2018
Joint reconstruction of rest/stress myocardial perfusion SPECT
Lai X, Petibon Y, Fakhri G, Ouyang J. Joint reconstruction of rest/stress myocardial perfusion SPECT. Physics In Medicine And Biology 2018, 63: 135019. PMID: 29897044, PMCID: PMC6245543, DOI: 10.1088/1361-6560/aacc2f.Peer-Reviewed Original ResearchConceptsMyocardial perfusion imagingSingle photon emission computed tomographyReversible defectsSignal-to-noise ratioRest/stress SPECT myocardial perfusion imagingSPECT myocardial perfusion imagingConventional subtraction methodDefect detectionJoint methodPhoton emission computed tomographySubtraction methodReverse mappingClinical dose levelsEmission computed tomographyImprove defect detectionLow noiseNon-invasive assessmentClinical dosePerfusion defectsReduced doseImprove radiologists' performanceReconstruction frameworkRest imagesPerfusion imagingDose levels
2017
Direct parametric reconstruction in dynamic PET myocardial perfusion imaging: in vivo studies
Petibon Y, Rakvongthai Y, Fakhri G, Ouyang J. Direct parametric reconstruction in dynamic PET myocardial perfusion imaging: in vivo studies. Physics In Medicine And Biology 2017, 62: 3539-3565. PMID: 28379843, PMCID: PMC5739089, DOI: 10.1088/1361-6560/aa6394.Peer-Reviewed Original ResearchConceptsPET sinogramsSignal-to-noise ratioList-mode PET dataSiemens Biograph mMR scannerList-mode dataMyocardial perfusion imagingNoise realizationsPET myocardial perfusion imagingLow count levelsLeast-squares fitBiograph mMR scannerPET projection dataOriginal list-mode dataMyocardial blood flowCount levelsParametric reconstructionOSEMReconstruction methodIndependent noise realizationsNormal count levelsSinogramDirect reconstructionDynamic sinogramsKinetic modelPoor signal-to-noise ratio
2016
Numerical observer for atherosclerotic plaque classification in spectral computed tomography
Lorsakul A, Fakhri G, Worstell W, Ouyang J, Rakvongthai Y, Laine A, Li Q. Numerical observer for atherosclerotic plaque classification in spectral computed tomography. Journal Of Medical Imaging 2016, 3: 035501-035501. PMID: 27429999, PMCID: PMC4940624, DOI: 10.1117/1.jmi.3.3.035501.Peer-Reviewed Original ResearchSignal-to-noise ratioChannelized Hotelling observerMatched filterSignal-to-noise ratio improvementDual-energy CTMultienergy CTSpectral computed tomographyBinary classification taskHotelling observerNumerical observationsArea under the receiver operating characteristic curveObjective image assessmentAcquisition methodImage atherosclerotic plaquesMaterial characterizationComputed tomographyClassification taskPerformance metricsAnthropomorphic digital phantomIdentification applicationsSpectral CT dataConventional CT systemsCalcified plaqueSignal variationsAnalytical computation
2014
4D 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 approachEffect 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 methodDetectionMotion compensation for brain PET imaging using wireless MR active markers in simultaneous PET–MR: Phantom and non-human primate studies
Huang C, Ackerman J, Petibon Y, Normandin M, Brady T, Fakhri G, Ouyang J. Motion compensation for brain PET imaging using wireless MR active markers in simultaneous PET–MR: Phantom and non-human primate studies. NeuroImage 2014, 91: 129-137. PMID: 24418501, PMCID: PMC3965607, DOI: 10.1016/j.neuroimage.2013.12.061.Peer-Reviewed Original ResearchConceptsMotion correctionWireless markersList-mode reconstructionReconstructed PET imagesMotion correction techniqueObserver signal-to-noise ratioSimultaneous PET-MRMotion artifactsPET phantomPET contrastPET reconstructionBrain PET imagingPET imagingPhantomBrain PETPET-MRIndependent noise realizationsAccurate quantitative valuesHead motionNoise realizationsPET dataSignal-to-noise ratioStatic referenceBrain PET scansActivation markers
2012
MRI-Based Nonrigid Motion Correction in Simultaneous PET/MRI
Chun Y, Reese T, Ouyang J, Guerin B, Catana C, Zhu X, Alpert N, Fakhri G. MRI-Based Nonrigid Motion Correction in Simultaneous PET/MRI. Journal Of Nuclear Medicine 2012, 53: 1284-1291. PMID: 22743250, PMCID: PMC4077320, DOI: 10.2967/jnumed.111.092353.Peer-Reviewed Original ResearchConceptsChannelized Hotelling observerMotion correctionDetection signal-to-noise ratioSignal-to-noise ratioMRI-based motion correctionRespiratory motion correctionMotion-corrected reconstructionOrdered-subsets expectation maximization algorithmNonrigid motion correctionChannelized Hotelling observer studyPET image qualityNonrigid image registration methodCoincidence dataDeformable phantomRespiratory gatingReduce radiation doseDynamic phantomImage registration methodReduced signal-to-noise ratioSimultaneous PET/MRICost of increased noiseHotelling observerPhantomAttenuation measurementsRabbit studies
2007
Fast Monte Carlo based joint iterative reconstruction for simultaneous SPECT imaging
Ouyang J, Fakhri G, Moore S. Fast Monte Carlo based joint iterative reconstruction for simultaneous SPECT imaging. Medical Physics 2007, 34: 3263-3272. PMID: 17879789, DOI: 10.1118/1.2756601.Peer-Reviewed Original ResearchConceptsMC-JOSEMEnergy windowFast Monte CarloSignal-to-noise ratioScatter correction methodOrdered-subsets expectation-maximizationMonte CarloOrdered-subsets expectation-maximization algorithmIterative reconstruction algorithmPrimary photonsReconstruction algorithmPhoton transportSeptal penetrationDetector responseMC simulationsIterative reconstructionAttenuation distributionStandard OSEMPhotonsProjection dataPatient-specific activityDetectorReconstructed imagesScatteringEstimation of scattering
2005
Performance of a novel collimator for high‐sensitivity brain SPECT
Fakhri G, Ouyang J, Zimmerman R, Fischman A, Kijewski M. Performance of a novel collimator for high‐sensitivity brain SPECT. Medical Physics 2005, 33: 209-215. PMID: 16485427, DOI: 10.1118/1.2143140.Peer-Reviewed Original ResearchConceptsSphere activity concentrationNPW-SNRStandard collimatorSphere-to-background activity ratiosAttenuation of countsPhantom centerActivity concentrationsPoint spread functionCentral regionCollimatorPhantom studyStriatal phantomCylindrical backgroundResolution recoveryPhantomSpherical lesionsRamp filterCrystal surfaceSpread functionSignal-to-noise ratioCentral brain structuresFitting imageHealthy volunteersBrain SPECTSphere activity
2004
Chapter 9 Annular Single-crystal Emission Tomography Systems
Genna S, Ouyang J, Xia W. Chapter 9 Annular Single-crystal Emission Tomography Systems. 2004, 169-178. DOI: 10.1016/b978-012744482-6.50012-0.Peer-Reviewed Original ResearchDepth of interactionRotating scintillation cameraAnnular crystalHigh-resolution small animal SPECTMultiple-pinhole collimatorScintillation cameraEmission tomography systemSmall-animal SPECTPulse pileSingle-photon emissionSPECT resolutionCollimatorAnimal SPECTSingle crystalsDedicated cameraSignal-to-noise ratioCamera geometryPositron emission tomographyTomography systemPET sensitivityCameraCamera systemCrystalBreast imagingParallax