2024
DIANA - Detectability Investgations using Artificial Nodal Additions
Bayerlein R, Xia M, Xie H, Spencer B, Ouyang J, Fakhri G, Nardo L, Liu C, Badawi R. DIANA - Detectability Investgations using Artificial Nodal Additions. 2024, 00: 1-1. DOI: 10.1109/nss/mic/rtsd57108.2024.10657528.Peer-Reviewed Original ResearchContrast recovery coefficientContrast-to-noise ratioLesion-to-background ratioList-mode dataTotal-body PET/CT scannerPositron emission tomographyContrast recoveryOSEM algorithmPatient motionPET/CT scannerArtificial lesionsImage quality metricsLesion detectionQuantitative accuracyPositron emission tomography scanRecovery coefficientCount densityImage contrastBody mass indexImage noisePositron emission tomography imaging techniquesFrame lengthImage smoothingActivity concentrationsAccuracy of lesion detection
2019
Limited-Angle TOF-PET for Intraoperative Surgical Application
Sajedi S, Bläckberg L, Vittum B, Devabhaktuni A, Nejad M, Fakhri G, Choi H, Sabet H. Limited-Angle TOF-PET for Intraoperative Surgical Application. 2019, 00: 1-4. DOI: 10.1109/nss/mic42101.2019.9059690.Peer-Reviewed Original ResearchSentinel lymph nodeHigh-resolution positron emission tomographyTOF-PETNear-infraredDetector ringDetector blockIncreasing acquisition timeTorso phantomHot spheresBottom detectorPositron emission tomographyTime resolutionDetectorIdentification of sentinel lymph nodesAcquisition timeSentinel lymph node identificationReconstructed imagesAccurate identification of sentinel lymph nodesActivity concentrationsWhole-body positron emission tomographyComplete tumor removalFalse negative rateImage slicesImprove patient recoveryPatient bedMR-based cardiac and respiratory motion correction of PET: application to static and dynamic cardiac 18F-FDG imaging
Petibon Y, Sun T, Han P, Ma C, Fakhri G, Ouyang J. MR-based cardiac and respiratory motion correction of PET: application to static and dynamic cardiac 18F-FDG imaging. Physics In Medicine And Biology 2019, 64: 195009. PMID: 31394518, PMCID: PMC7007962, DOI: 10.1088/1361-6560/ab39c2.Peer-Reviewed Original ResearchConceptsMR-based motion correctionRespiratory motion correctionMotion correctionImproved spatial resolutionReconstructed activity concentrationCardiac PET dataSpatial resolutionCoincidence eventsMR-basedPET imagingContrast-to-noise ratioCardiac PET imagingRespiratory phasesMC dataImprove image qualityMR acquisitionQuantitative accuracyCardiac PETPET dataActivity concentrationsMyocardium wallF-FDG PETDynamics studiesImage qualityMotion artifacts
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 cm
2008
Sequential and simultaneous dual‐isotope brain SPECT: Comparison with PET for estimation and discrimination tasks in early Parkinson disease
Trott C, Fakhri G. Sequential and simultaneous dual‐isotope brain SPECT: Comparison with PET for estimation and discrimination tasks in early Parkinson disease. Medical Physics 2008, 35: 3343-3353. PMID: 18697558, PMCID: PMC2673561, DOI: 10.1118/1.2940605.Peer-Reviewed Original ResearchConceptsEnergy resolutionTime-of-flight PET scannerRealistic Monte Carlo simulationsAcquisition energy windowSequential SPECTSystem energy resolutionGamma cameraEnergy windowThree-head cameraPET scannerEmission energyMonte Carlo simulationsDual-isotope SPECTSimultaneous SPECTBrain PETTwo-headed cameraCarlo simulationsProdromal disease stagesIdentical physiological conditionsSpatial resolutionDiscrimination taskStriatal sizeActivity concentrationsEarly identification of PDCamera headImproved 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
Comparison of Brain PET and Sequential and Simultaneous Dual-isotope SPECT for Estimation Tasks in Normal and Parkinson Subjects
Trott C, Fakhri G. Comparison of Brain PET and Sequential and Simultaneous Dual-isotope SPECT for Estimation Tasks in Normal and Parkinson Subjects. 2007, 5: 3616-3620. DOI: 10.1109/nssmic.2007.4436906.Peer-Reviewed Original ResearchDopamine transporterEarly stages of PDDual-isotope SPECTStages of PDSequential SPECTDisease stageSimultaneous dual-isotope studyStriatal sizeBrain functionImprove patient managementEstimation taskDual-isotope studiesBrain PETDopamineClinical symptomsParkinson's diseasePatient managementSPECT imagesSpecific bindingMotor functionSPECTBrainEarly detectionActivity concentrationsIdentical physiological conditions
2006
Monte Carlo-based compensation for patient scatter, detector scatter, and crosstalk contamination in In-111 SPECT imaging
Moore S, Ouyang J, Park M, Fakhri G. Monte Carlo-based compensation for patient scatter, detector scatter, and crosstalk contamination in In-111 SPECT imaging. Nuclear Instruments And Methods In Physics Research Section A Accelerators Spectrometers Detectors And Associated Equipment 2006, 569: 472-476. DOI: 10.1016/j.nima.2006.08.079.Peer-Reviewed Original ResearchScatter projectionsPatient scatterDetector scatterOrgan activity estimatesPhoton interaction pointIterative reconstruction algorithmDetector effectsEnergy binsReconstruction algorithmDelta scatteringTorso phantomPoint spread functionSegmented CT scanInteraction pointOSEM reconstructionNumerical phantomDetectorScatteringScattering mapSpherical tumorSpread functionImage noisePhantomActivity concentrationsActivity estimationQuantitative Analysis of PET Reconstruction Techniques over a Wide Activity Range with 2D and 3D Acquisition Modes
Wollenweber S, Fakhri G, Moore S. Quantitative Analysis of PET Reconstruction Techniques over a Wide Activity Range with 2D and 3D Acquisition Modes. 2006, 4: 2233-2235. DOI: 10.1109/nssmic.2006.354358.Peer-Reviewed Original ResearchPositron emission tomographicField of viewFiltered backprojectionEstimation of activity concentrationImaging field of viewQuantitative imaging performanceIterative reconstruction methodValues of activity concentrationsActivity concentrationsPET-CT systemFBP imagesScan modeReconstruction methodROI valuesImaging performanceAnalytical reconstructionEmission tomographicRegions-of-interestROI activityPET-CTPhantomOSEMF-18BackprojectionTissue background
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
2002
Optimization of Ga‐67 imaging for detection and estimation tasks: Dependence of imaging performance on spectral acquisition parameters
Fakhri G, Moore S, Kijewski M. Optimization of Ga‐67 imaging for detection and estimation tasks: Dependence of imaging performance on spectral acquisition parameters. Medical Physics 2002, 29: 1859-1866. PMID: 12201433, DOI: 10.1118/1.1493214.Peer-Reviewed Original ResearchConceptsIdeal signal-to-noise ratioEnergy windowSignal-to-noise ratioMonte Carlo programDetection of spheresTorso phantomPhantom acquisitionsSphere of radiusEstimation taskPhantom dataLower-energyGa-67 imagingPhantomAcquisition parametersActivity concentrationsSpectral acquisition parametersGa-67Sphere sizeEnergyPhotopeakTumor imagingOptimal windowTaskClinicMonteOptimal Parallel-Hole Collimation for Lesion Detection and Activity Estimation in Ga-67 Imaging
Moore S, Kijewski M, Fakhri G. Optimal Parallel-Hole Collimation for Lesion Detection and Activity Estimation in Ga-67 Imaging. 2002, 3: 1390-1392. DOI: 10.1109/nssmic.2002.1239580.Peer-Reviewed Original ResearchCollimator designMedium-energy (MESimulation of photon transportSignal-to-noise ratioParallel-hole collimatorDesign of collimatorsClinical imaging tasksGa-67Contaminating photonsField of nuclear medicineEnergy windowFixed energyPhoton transportOptimal collimatorCollimatorCommercial collimatorsStaging of lymphoma patientsHotelling observerGa-67 imagingNuclear medicine clinicsLesion detectionNuclear medicineDetectorActivity concentrationsResolution values
2001
Absolute 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
Relative lesion detectability in 3D vs. 2D dedicated multi-ring PET
Moore S, Fakhri G, Badawi R, Van den Abbeele A, Zimmerman R. Relative lesion detectability in 3D vs. 2D dedicated multi-ring PET. 2011 IEEE Nuclear Science Symposium Conference Record 2000, 3: 17/18-17/22 vol.3. DOI: 10.1109/nssmic.2000.949192.Peer-Reviewed Original ResearchField of viewNon-prewhiteningAxial field-of-viewMaximum ring differenceAnthropomorphic torso phantomClinically realistic phantomDetection of spheresNPW-SNRTorso phantomGe-68Head phantomDetection signal-to-noise ratioRing differenceRealistic phantomsPhantomBed positionF-18Signal-to-noise ratioActivity concentrationsTwo-dimensionalContrast levelsPET imagingCompare two-dimensionalModeFORE+FBP