2024
Integration of a continuously varying image-space PSF for a dual-panel ultra-high TOF-PET scanner
Chemli Y, Marin T, Orehar M, Dolenec R, Normandin M, Gascón D, Gola A, Grogg K, Pavón G, Razdevsek G, Pestotnik R, Fakhri G. Integration of a continuously varying image-space PSF for a dual-panel ultra-high TOF-PET scanner. 2024, 00: 1-1. DOI: 10.1109/nss/mic/rtsd57108.2024.10656225.Peer-Reviewed Original ResearchGaussian mixture modelGaussian process regressionPoint spread functionAccurate image reconstructionMaximum likelihood estimation maximizationShift-variant convolutionsImage reconstructionMixture modelProcess regressionEstimation maximizationTime-of-flight (TOFPanel architectureSpread functionArchitectureParameter interpolationHigh resolution time-of-flight (TOFTOF-PET scannerBrain phantomFitting processPositron emission tomography scannerSimulated point sourcesConvolutionAlgorithmEffective diagnosisSize benefits
2023
Imaging 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 rods
2016
Direct Parametric Imaging of Reversible Tracers Using Partial Dynamic Data
Kim K, Fakhri G, Li Q. Direct Parametric Imaging of Reversible Tracers Using Partial Dynamic Data. 2016, 1-4. DOI: 10.1109/nssmic.2016.8069385.Peer-Reviewed Original Research
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 cmPenalized Direct Estimation of Parametric Images in PET
Kim K, Fakhri G, Li Q. Penalized Direct Estimation of Parametric Images in PET. 2015, 1-4. DOI: 10.1109/nssmic.2015.7582182.Peer-Reviewed Original ResearchAlternating direction methodDirection methodHigh noise varianceIterative reconstruction processKinetic parameter imagesTV regularizationNoise varianceDirect reconstructionPhysiological kinetic parametersDirection estimationReconstruction processNeighboring voxelsCost functionRidge regressionRaw measurementsConventional direct methodComputer simulationsDynamic imagingSplitting methodKinetic parametersImagesBrain phantomAccurate parametric imagesPoisson likelihoodPotential images
2002
Quantitative Simultaneous 99MTc/123I Spect: Design Study and Validation With Monte Carlo Simulations and Physical Acquisitions
Fakhri G, Maksud P, Kijewski M, Zimmerman R, Moore S. Quantitative Simultaneous 99MTc/123I Spect: Design Study and Validation With Monte Carlo Simulations and Physical Acquisitions. IEEE Transactions On Nuclear Science 2002, 49: 2315. DOI: 10.1109/tns.2002.803819.Peer-Reviewed Original ResearchMonte Carlo simulationsBrain phantomCarlo simulationsSimultaneous dual-isotope imagingIterative ordered subsetsDigital brain phantomDual-isotope SPECT studyVariable collimator responseArtificial neural networkPhysical acquisitionEnergy windowNonuniform attenuationCollimator responseDual-isotope imagingPhantom acquisitionsScatter correctionClinical cameraNeural networkMontePhantomIsotope imagingCorrected projectionsSPECT studiesProjector/backprojectorClinical application
2001
Absolute Activity Quantitation From Projections Using an Analytical Approach: Comparison With Iterative Methods in Tc-99M and I-123 Brain SPECT
Fakhri G, Kijewski M, Moore S. Absolute Activity Quantitation From Projections Using an Analytical Approach: Comparison With Iterative Methods in Tc-99M and I-123 Brain SPECT. IEEE Transactions On Nuclear Science 2001, 48: 768. DOI: 10.1109/23.940161.Peer-Reviewed Original ResearchVariable collimator responseI-123 studiesOrdered subsets-expectation maximizationI-123Tc-99mTc-99Brain phantomAttenuation correctionAnthropomorphic brain phantomDigital brain phantomTc-99m studiesMonte Carlo simulated projectionsCollimator responseActivity quantitationPathological patientsBrain structuresBrain SPECTActivity distributionPoor spatial resolutionSPECT activityQuantitative accuracyFitting procedurePartial volume effectsCaudate nucleusCorpus callosumAbsolute activity quantitation in simultaneous 123I/99mTc brain SPECT.
El Fakhri G, Moore S, Maksud P, Aurengo A, Kijewski M. Absolute activity quantitation in simultaneous 123I/99mTc brain SPECT. Journal Of Nuclear Medicine 2001, 42: 300-8. PMID: 11216530.Peer-Reviewed Original ResearchMeSH KeywordsAlzheimer DiseaseBenzamidesBrainCerebellumCerebral CortexCerebrovascular CirculationCorpus CallosumHumansIodine RadioisotopesMonte Carlo MethodNeural Networks, ComputerParkinson DiseasePhantoms, ImagingPutamenPyrrolidinesRadiopharmaceuticalsSensitivity and SpecificityTechnetium Tc 99m ExametazimeTomography, Emission-Computed, Single-PhotonConceptsOrdered-subset expectation maximizationDistance-dependent collimator responseActivity quantitationActivity distributionIterative ordered-subsets expectation maximizationZubal brain phantomAsymmetric windowsSimulated normal populationPathological studiesDecay photonsBrain SPECTCollimator responseNonuniform attenuationDual-isotope imagingBrain phantomMonte Carlo simulationsCorpus callosumNormal populationPartial volume effectsCarlo simulationsCortical lobesAssessment of brain perfusionScatteringCross-talkBrain perfusionAbsolute Quantitation in Simultaneous 99mTc/123I Brain SPECT Using ANN: Design Optimization and Validation
Fakhri G, Maksud P, Moore S, Zimmerman R, Kijewski M. Absolute Quantitation in Simultaneous 99mTc/123I Brain SPECT Using ANN: Design Optimization and Validation. 2001, 3: 1429-1431. DOI: 10.1109/nssmic.2001.1008605.Peer-Reviewed Original ResearchMonte Carlo simulationsBrain phantomSimultaneous dual-isotope imagingDigital brain phantomDual-isotope SPECT studyVariable collimator responseCarlo simulationsNon-uniform attenuationI-123 imagingEnergy windowCollimator responseDual-isotope imagingPhantom acquisitionsOSEM algorithmArtificial neural networkPhysical acquisitionScatter correctionClinical cameraBrain structuresPhantomIsotope imagingMonteSPECT studiesActivity concentrationsTc-99
2000
Scatter and cross-talk corrections in simultaneous Tc-99m/I-123 brain SPECT using constrained factor analysis and artificial neural networks
Fakhri G, Maksud P, Kijewski M, Haberi M, Todd-Pokropek A, Aurengo A, Moore S. Scatter and cross-talk corrections in simultaneous Tc-99m/I-123 brain SPECT using constrained factor analysis and artificial neural networks. IEEE Transactions On Nuclear Science 2000, 47: 1573-1580. DOI: 10.1109/23.873018.Peer-Reviewed Original ResearchSpectral factor analysisTc-99mEnergy window methodDigital brain phantomCross-talk correctionI-123 imagingUnscattered photonsTc-99m activityBrain phantomMonte Carlo simulationsI-123Dual-isotope studiesPhotonsCarlo simulationsTc-99Simultaneous imagingAssessment of brain perfusionCross-talkBrain structuresBrain SPECTArtificial neural networkBrain perfusionPhantomClinical potentialCaudate nucleusAbsolute activity quantitation from projections using an analytical approach: comparison with iterative methods in brain SPECT
Fakhri G, Kijewski M, Moore S. Absolute activity quantitation from projections using an analytical approach: comparison with iterative methods in brain SPECT. 2011 IEEE Nuclear Science Symposium Conference Record 2000, 3: 18/7-1811 vol.3. DOI: 10.1109/nssmic.2000.949215.Peer-Reviewed Original ResearchVariable collimator responseI-123 studiesI-123Tc-99Attenuation correctionTc-99mBrain SPECTDigital brain phantomTc-99m studiesMonte Carlo simulated projectionsCollimator responseActivity quantitationActivity estimationBrain phantomOSEM algorithmBrain structuresActivity distributionAccurate quantitationPoor spatial resolutionSPECT activityFitting procedurePartial volume effectsCaudate nucleusCorpus callosumSpatial resolution
1999
A new correction method for cross-talk using artificial neural networks: validation in simultaneous technetium and iodine cerebral imaging
Fakhri G, Maksud P, Habert M, Todd-Pokropek A, Aurengo A. A new correction method for cross-talk using artificial neural networks: validation in simultaneous technetium and iodine cerebral imaging. 2011 IEEE Nuclear Science Symposium Conference Record 1999, 2: 1000-1004 vol.2. DOI: 10.1109/nssmic.1999.845830.Peer-Reviewed Original ResearchEnergy window methodMonte CarloHuman brain phantomI-123 imagingGeometric phantomsBrain phantomMC simulationsTc-99mCorrection methodDual-isotope studiesActivity distributionM imagesI-123PhantomAssessment of brain perfusionCross-talkRadionuclidesTc-99Cerebral imagingCorrectionBrain perfusionClinical potentialBackprojectionMonteCarloMonte Carlo evaluation of quantitation in simultaneous Tc-99m/I-123 brain SPECT using constrained spectral factor analysis
Fakhri G, Moore S, Kijewski M, Maksud P, Todd-Pokropek A. Monte Carlo evaluation of quantitation in simultaneous Tc-99m/I-123 brain SPECT using constrained spectral factor analysis. 2011 IEEE Nuclear Science Symposium Conference Record 1999, 3: 1392-1396 vol.3. DOI: 10.1109/nssmic.1999.842815.Peer-Reviewed Original ResearchSpectral factor analysisTc-99mEnergy window methodDigital brain phantomI-123 imagingUnscattered photonsTc-99m activityBrain phantomFiltered-backprojectionMonte Carlo simulationsPrimary spectraDual-isotope studiesI-123Monte Carlo evaluationPhotonsCarlo simulationsSimultaneous imagingMonteBrain structuresBrain SPECTTc-99PhantomCaudate nucleusSpectraPixel values