2024
Flat Panel TOF-PET Detectors: a Simulation Study
Orehar M, Dolenec R, Fakhri G, Gascón D, Gola A, Korpar S, Križan P, Razdevšek G, Marin T, Chemli Y, Žontar D, Pestotnik R. Flat Panel TOF-PET Detectors: a Simulation Study. 2024, 00: 1-2. DOI: 10.1109/nss/mic/rtsd57108.2024.10658250.Peer-Reviewed Original ResearchTime resolutionAngular coverageFlat-panel detectorScintillation materialsGATE softwareAxial coverageBiograph VisionPanel detectorTotal-body coverageClinical scannerImage reconstructionDetectorReconstructed imagesHomogeneous contrastCylindrical scannerImage qualityState-of-the-artScintillationHigh-performance computingScannerPhantomResolutionCore hoursPositron emission tomographyGateAccelerated 3D metabolite T1 mapping of the brain using variable‐flip‐angle SPICE
Zhao Y, Li Y, Guo R, Jin W, Sutton B, Ma C, Fakhri G, Li Y, Luo J, Liang Z. Accelerated 3D metabolite T1 mapping of the brain using variable‐flip‐angle SPICE. Magnetic Resonance In Medicine 2024, 92: 1310-1322. PMID: 38923032, DOI: 10.1002/mrm.30200.Peer-Reviewed Original ResearchConceptsLow-rank tensor modelGeneralized series modelMetabolite TExperimental resultsBrain metabolitesClinically acceptable scan timeEfficient encodingPhantom experimental resultsAcceptable scan timeNoisy dataSparse samplingImaging problemsData processingHealthy subject dataVariable flip angleFlip angleTensor modelSaturation effectsQuantitative metabolic imagingMRSI techniquePhantomScan timeData acquisitionMetabolic imagingT1 mapping
2023
Simulation results for limited-angle ultra-high time-of-flight resolution PET system
Marin T, Zhuo Y, Orehar M, Razdevšekc G, Dolenec R, Mounime I, Alamo J, Benlloch J, Chemli Y, Fernández-Tenllado J, Gascon D, Gola A, Gomez S, Grogg K, Guberman D, Korpar S, Krizan P, Majewski S, Manera R, Mariscal-Castilla A, Mauricio J, Merzi S, Morera C, Normandin M, Pavon G, Penna M, Seljak A, Studen A, Pestotnik R, Fakhri G. Simulation results for limited-angle ultra-high time-of-flight resolution PET system. 2023, 00: 1-1. DOI: 10.1109/nssmicrtsd49126.2023.10337821.Peer-Reviewed Original ResearchResolution PET systemsPET systemAxial fieldPositron emission tomography systemPositron emission tomography scannerTotal-body PET systemsLong axial fieldTOF resolutionNovel detectorNumerical phantomHigh-sensitivity systemMonte-Carlo simulationsSpatial resolutionPositron emission tomographyMonte-CarloSystem sensitivityImage resolutionImage qualityScintillationReconstruction engineFWHMResolutionTOFPhantomScannerImaging Performance of the Fully Assembled Ultra-High Resolution (UHR) Brain PET scanner
Loignon-Houle F, Toussaint M, Beaudoin J, Gaudreault M, Doyon V, Leroux J, Auger E, Thibaudeau C, Arpin L, Croteau E, Espinosa-Bentancourt E, Samson A, Bouchard J, Espagnet R, Viscogliosi N, Pepin C, Labrecque V, Paulin C, Marin T, Ouyang J, Normandin M, Tétrault M, Michaud J, Fontaine R, Fakhri G, Lecomte R. Imaging Performance of the Fully Assembled Ultra-High Resolution (UHR) Brain PET scanner. 2023, 00: 1-1. DOI: 10.1109/nssmicrtsd49126.2023.10338146.Peer-Reviewed Original ResearchBrain PET scannerUltra-high resolutionPET scannerPeak noise-equivalent count rateUltra Micro Hot Spot PhantomNoise-equivalent count rateAxial field-of-viewHot spot phantomHoffman brain phantomSmall-scale structuresCount rateBrain phantomContrast recoveryReadout schemeField of viewBrain PET imagingPhantomExcellent image qualityImaging performanceSpatial resolutionSmall structuresUltrahigh resolutionImage qualityPET imagingLarger rodsImpact of motion correction on [18F]-MK6240 tau PET imaging
Tiss A, Marin T, Chemli Y, Spangler-Bickell M, Gong K, Lois C, Petibon Y, Landes V, Grogg K, Normandin M, Becker A, Thibault E, Johnson K, Fakhri G, Ouyang J. Impact of motion correction on [18F]-MK6240 tau PET imaging. Physics In Medicine And Biology 2023, 68: 105015. PMID: 37116511, PMCID: PMC10278956, DOI: 10.1088/1361-6560/acd161.Peer-Reviewed Original ResearchConceptsMotion correctionPET quantitationImpact of motion correctionList-mode reconstructionMotion correction methodList-mode dataMotion-corrected imagesEffect of motion correctionVoxel displacementsPhantom experimentsOptical tracking dataLong acquisitionBrain PET scansSlow motionImage qualityPET imagingPositron emission tomographyCorrectionMotionCorrection methodRates of tau accumulationHead motionMotion metricsPhantomPositronSuper-resolution in brain positron emission tomography using a real-time motion capture system
Chemli Y, Tétrault M, Marin T, Normandin M, Bloch I, El Fakhri G, Ouyang J, Petibon Y. Super-resolution in brain positron emission tomography using a real-time motion capture system. NeuroImage 2023, 272: 120056. PMID: 36977452, PMCID: PMC10122782, DOI: 10.1016/j.neuroimage.2023.120056.Peer-Reviewed Original ResearchConceptsBrain positron emission tomographySuper-resolutionEvent-by-event basisReal-time motion capture systemSR reconstruction methodTracking cameraVisualization of small structuresPET reconstruction algorithmMoving phantomMeasure target motionLine profilesPET/CT scannerMeasured shiftsImprove image resolutionMotion capture systemMotion tracking devicePositron emission tomographyReconstruction algorithmSpatial resolutionMeasured linesPhantomReal-timeEstimation frameworkIncreased spatial resolutionReconstruction method
2022
Optimization of Design Parameters of Flat Panel Limited Angle TOF-PET Scanner: a Simulation Study
Orehar M, Dolenec R, Fakhri G, Gascón D, Gola A, Korpar S, Križan P, Razdevšek G, Pestotnik R. Optimization of Design Parameters of Flat Panel Limited Angle TOF-PET Scanner: a Simulation Study. 2022, 00: 1-4. DOI: 10.1109/nss/mic44845.2022.10399330.Peer-Reviewed Original ResearchImage quality phantomFlat-panel detectorGATE softwareRing scannerPanel detectorDetection chainState-of-the-artNEMA standardsOpen geometryImage reconstructionReconstructed imagesPositron emission tomographyState-of-the-art scannersScannerPhantomDetectorPhotodetectorsElectronNEMAMaterial costGatePositron
2020
Limited-angle TOF-PET for intraoperative surgical applications: latest results
Sajedi S, Bläckberg L, Fakhri G, Sabet H. Limited-angle TOF-PET for intraoperative surgical applications: latest results. 2020, 00: 1-3. DOI: 10.1109/nss/mic42677.2020.9507853.Peer-Reviewed Original ResearchCoincidence time resolutionWater phantomTOF-PETSphere-to-background activity ratiosLesion phantomsPET detector moduleDepth of interactionPET detector technologySmall-area detectorsDiameter spheresTime-of-flight (TOFPhantom depthDetector modulesCrystal pixelsDetector technologyDetector headFlight (TOFTime resolutionPhantomReduce FNRDetectorConventional gammaLarger-areaPixel dimensionsAngle geometryMR‐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 ResearchConceptsLinear 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
Body motion detection and correction in cardiac PET: Phantom and human studies
Sun T, Petibon Y, Han P, Ma C, Kim S, Alpert N, Fakhri G, Ouyang J. Body motion detection and correction in cardiac PET: Phantom and human studies. Medical Physics 2019, 46: 4898-4906. PMID: 31508827, PMCID: PMC6842053, DOI: 10.1002/mp.13815.Peer-Reviewed Original ResearchConceptsList-mode dataMotion-compensated image reconstructionMotion correctionCenter of massPET list-mode dataMotion correction methodMotion detectionMotion estimationImage reconstructionPatient body motionDegrade image qualityNonrigid registrationImage qualityMotion transformationCoincident distributionBody motion detectionCardiac positron emission tomographyBack-projection techniqueCovariance matrixImage volumesBody motionPositron emission tomographyBack-projectionReference framePhantomPET Image Deblurring and Super-Resolution With an MR-Based Joint Entropy Prior
Song T, Yang F, Chowdhury S, Kim K, Johnson K, Fakhri G, Li Q, Dutta J. PET Image Deblurring and Super-Resolution With an MR-Based Joint Entropy Prior. IEEE Transactions On Computational Imaging 2019, 5: 530-539. PMID: 31723575, PMCID: PMC6853071, DOI: 10.1109/tci.2019.2913287.Peer-Reviewed Original ResearchContrast-to-noise ratioStructural similarity indexHoffman phantomImage deblurringDigital phantomPhantom studyPeak signal-to-noise ratioSuper-resolution frameworkQuantitative accuracySimilarity indexSignal-to-noise ratioSpatial resolutionPhantomImage quantitationSuper-resolutionTau imaging studiesImage qualityPET imagingDeblurringHigh-resolution MR imagingRoot mean square errorSimulation studyBrainWebPost-processingPenalty function
2017
Magnetic 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 imagingJoint reconstruction of Ictal/inter‐ictal SPECT data for improved epileptic foci localization
Rakvongthai Y, Fahey F, Borvorntanajanya K, Tepmongkol S, Vutrapongwatana U, Zukotynski K, Fakhri G, Ouyang J. Joint reconstruction of Ictal/inter‐ictal SPECT data for improved epileptic foci localization. Medical Physics 2017, 44: 1437-1444. PMID: 28211105, PMCID: PMC5462456, DOI: 10.1002/mp.12167.Peer-Reviewed Original ResearchConceptsSPECT reconstruction methodDifferential imagingLow-noise datasetConventional subtraction methodLesion contrastSPECT projection dataEpileptic focus localizationHoffman phantomPatient studiesReconstruction methodJoint methodSPECT projectionsHead phantomPhantom locationsSubtraction methodPhantom studyNuclear medicine physiciansAttenuation backgroundPhantomConventional subtraction approachFocus localizationConventional subtractionReceiver operating characteristicLow noiseProjection dataFeasibility study of using fall‐off gradients of early and late PET scans for proton range verification
Cho J, Grogg K, Min C, Zhu X, Paganetti H, Lee H, Fakhri G. Feasibility study of using fall‐off gradients of early and late PET scans for proton range verification. Medical Physics 2017, 44: 1734-1746. PMID: 28273345, PMCID: PMC5462437, DOI: 10.1002/mp.12191.Peer-Reviewed Original ResearchConceptsProton range verificationProton rangeMonte Carlo simulationsRange verificationFall-offIn-room positron emission tomographyCarlo simulationsResidual proton rangeDose fall-offPostirradiation delayPositron emission tomography imagingSOBP beamProton beamPositron emission tomographyPositron emission tomography scanPhantom studyIn-roomFunction of depthPhantomProtonOff-setMonteAcquisition timeBeamPositron emission tomography signal
2016
GATE Simulation of a High-Performance Stationary SPECT System for Cardiac Imaging
Uzun-Özşahin D, Bläckberg L, Moghadam N, Fakhri G, Sabet H. GATE Simulation of a High-Performance Stationary SPECT System for Cardiac Imaging. 2016, 1-3. DOI: 10.1109/nssmic.2016.8069814.Peer-Reviewed Original ResearchPoint spread functionDerenzo-like phantomGATE simulated resultsGATE simulation studiesSystem spatial resolutionStationary SPECT systemGATE simulationsSPECT systemMultiple simultaneous viewsCardiac imaging applicationsActive rodsSpread functionSpatial resolutionImaging applicationsImage reconstructionGateCorrection techniqueFWHMContouring systemPhantomResolutionLaserCardiac imagingInvestigation of cone-beam CT image quality trade-off for image-guided radiation therapy
Bian J, Sharp G, Park Y, Ouyang J, Bortfeld T, Fakhri G. Investigation of cone-beam CT image quality trade-off for image-guided radiation therapy. Physics In Medicine And Biology 2016, 61: 3317-3346. PMID: 27032676, DOI: 10.1088/0031-9155/61/9/3317.Peer-Reviewed Original ResearchConceptsImage-guided radiation therapyCone-beam CTFiltered-backprojectionImage quality trade-offConventional filtered-backprojectionShort-scan reconstructionsFiltered-backprojection algorithmFan-beam reconstructionTV-based algorithmIterative reconstruction algorithmCatphan phantomRadiation therapyAngular rangeTotal-variationOptimal exposure levelClinical scannerScanning configurationReconstruction algorithmImaging conditionsCatphanPhantomExposure levelsTherapyConfigurationRange
2015
National Electrical Manufacturers Association and Clinical Evaluation of a Novel Brain PET/CT Scanner
Grogg K, Toole T, Ouyang J, Zhu X, Normandin M, Li Q, Johnson K, Alpert N, Fakhri G. National Electrical Manufacturers Association and Clinical Evaluation of a Novel Brain PET/CT Scanner. Journal Of Nuclear Medicine 2015, 57: 646-652. PMID: 26697961, PMCID: PMC4818715, DOI: 10.2967/jnumed.115.159723.Peer-Reviewed Original ResearchConceptsNoise-equivalent count rateCount rateLoose cutsMaximum noise-equivalent counting rateSpatial resolutionDetector ringSilicon photomultipliersBrain phantomContrast recoveryAttenuation correctionPET/CT systemCrystal blockPET/CT scannerImage qualityRadial offsetNational Electrical Manufacturers AssociationActivity distributionUnique mobility capabilitiesAxial extentTransverse resolutionPhantomAxial resolutionActivity concentrationsHuman scansLayer 1 cmFast Estimation of Image Variance for Time-of-flight PET Reconstruction
Wang M, Hu G, Fakhri G, Zhang H, Li Q. Fast Estimation of Image Variance for Time-of-flight PET Reconstruction. 2015, 1-4. DOI: 10.1109/nssmic.2015.7582040.Peer-Reviewed Original ResearchImage varianceMaximum likelihood expectation maximizationTOF-PETAhstract-The useLikelihood expectation maximizationFast algorithmExpectation maximizationReduction of computation timeComputation timeImage qualityMonte Carlo simulationsUniform diskFast estimationAlgorithmAnalytical expressionsCarlo simulationsVariance predictionImagesPET imagingPositron emission tomographyPhantomMaximizationContinuous MR bone density measurement using water- and fat-suppressed projection imaging (WASPI) for PET attenuation correction in PET-MR
Huang C, Ouyang J, Reese T, Wu Y, Fakhri G, Ackerman J. Continuous MR bone density measurement using water- and fat-suppressed projection imaging (WASPI) for PET attenuation correction in PET-MR. Physics In Medicine And Biology 2015, 60: n369-n381. PMID: 26405761, PMCID: PMC4607313, DOI: 10.1088/0031-9155/60/20/n369.Peer-Reviewed Original ResearchConceptsAttenuation correctionUltrashort echo timeMR-based attenuation correctionProjection imagesPET attenuation correctionMR attenuation correctionPET-MRPulse sequenceEcho timeDensity variationsPET imagingCorrectionBone density variationWASPIDensity measurementsAttenuation variationsPhantomMR sequencesLack of signalPulseAttenuationPET Point Spread Function Modeling and Image Deblurring Using a PET/MRI Joint Entropy Prior
Dutta J, Fakhri G, Zhu X, Li Q. PET Point Spread Function Modeling and Image Deblurring Using a PET/MRI Joint Entropy Prior. 2015, 1423-1426. DOI: 10.1109/isbi.2015.7164143.Peer-Reviewed Original ResearchJoint entropyDe-blurring techniqueImage deblurringBrain WebQuantitative accuracy of PETImage spaceEfficient frameworkDeconvolution problemDeblurringCost functionPoint spread function modelPenalty functionHuman datasetsSpatial resolution capabilitiesPET scannerAmplifier noisePET imagingImagesConsistent with MRIQuantitative accuracyPartial volume effectsPhantomDatasetEntropyFunction model