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
Numerical Observer for Objective Assessment on Carotid Plaque Using Spectral CT
Lorsakul A, Fakhri G, Ouyang J, Worstell W, Rakvongthai Y, Laine A, Li Q. Numerical Observer for Objective Assessment on Carotid Plaque Using Spectral CT. 2014, 1-4. DOI: 10.1109/nssmic.2014.7430906.Peer-Reviewed Original ResearchMulti-energy CTNumerical observationsCarotid plaquesMatched filterCT systemDigital anthropomorphic phantomHotelling observerDual-energyPlaque featuresImage binConventional CT imagesConventional CT systemsChannelized Hotelling observerAnthropomorphic phantomClassification performanceCT imagesSpectral CTCalcified plaqueClinical classification taskProcessing stepsSimulated imagesPlaqueSuperior performance4D 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 approachTowards 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 imagingPhantomMyocardial Defect Detection Using PET-CT: Phantom Studies
Mananga E, Fakhri G, Schaefferkoetter J, Bonab A, Ouyang J. Myocardial Defect Detection Using PET-CT: Phantom Studies. PLOS ONE 2014, 9: e88200. PMID: 24505429, PMCID: PMC3914931, DOI: 10.1371/journal.pone.0088200.Peer-Reviewed Original ResearchConceptsMyocardial defect detectionFiltered back projectionChannelized Hotelling observerPhantom studyActivity distributionSubset expectation maximizationDefect detectionCardiac PET studiesMyocardial defectsHotelling observerNoise levelBack-projectionPET-CTPhantomExpectation maximizationOP-OSEMReconstruction schemePET studiesOSEMDefectsNoise
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
Impact of Acquisition Geometry, Image Processing, and Patient Size on Lesion Detection in Whole-Body 18F-FDG PET
Fakhri G, Santos P, Badawi R, Holdsworth C, Van Den Abbeele A, Kijewski M. Impact of Acquisition Geometry, Image Processing, and Patient Size on Lesion Detection in Whole-Body 18F-FDG PET. Journal Of Nuclear Medicine 2007, 48: 1951-1960. PMID: 18006613, DOI: 10.2967/jnumed.108.007369.Peer-Reviewed Original ResearchConceptsAttenuation-weighted OSEMOrdered-subset expectation maximizationNoise equivalent countPhantom sizeBed positionCho SNRPatient sizeFourier rebinningAttenuation mapPET scannerLesion detectionMarginal detectionTransmission scanWhole-body (18)F-FDG PETAttenuation correctionWhole-body 18F-FDG PETHotelling observerScaling 2DSinogramReconstructed volumeDetection SNRPhantomSystematic improvementFBPScattering
2005
Collimator Optimization for Detection and Quantitation Tasks: Application to Gallium-67 Imaging
Moore S, Kijewski M, Fakhri G. Collimator Optimization for Detection and Quantitation Tasks: Application to Gallium-67 Imaging. IEEE Transactions On Medical Imaging 2005, 24: 1347-1356. PMID: 16229420, DOI: 10.1109/tmi.2005.857211.Peer-Reviewed Original ResearchMeSH KeywordsCitratesComputer SimulationComputer-Aided DesignEquipment DesignEquipment Failure AnalysisGalliumHumansImage EnhancementImage Interpretation, Computer-AssistedModels, BiologicalNeoplasmsPhantoms, ImagingPositron-Emission TomographyRadiopharmaceuticalsReproducibility of ResultsSensitivity and SpecificityConceptsMedium-energy low-penetration collimatorCollimator optimizationGeometric spatial resolutionPhotopeak energy windowSimulation of photon transportLead X-raysClinical imaging tasksActivity estimation taskSignal-to-noise ratioGallium-67 imagingContaminating photonsEnergy windowGeometric efficiencyCollimator designFixed energyPhoton transportOptimal collimatorCollimatorHotelling observerFWHMSpatial resolutionNuclear medicineDetectorResolution valuesImaging tasks
2003
Evaluation of a Monte Carlo Scatter Correction in Clinical 3D PET
Holdsworth C, Badawi R, Santos P, Van den Abbeele A, Hoffman E, Fakhri G. Evaluation of a Monte Carlo Scatter Correction in Clinical 3D PET. 2003, 4: 2540-2544. DOI: 10.1109/nssmic.2003.1352408.Peer-Reviewed Original ResearchScatter correctionUncorrected imagesPET imagingChannelized Hotelling observerHotelling observerPatient dataPatient imagesQuantitative accuracyLesion detection sensitivityPatient sizePhantomLesion sensitivityPatientsMonteLesionsLesion detectionCorrectionROI analysisIntensity varianceDetection sensitivityPETScatteringAverage absolute bias
2002
Optimal 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 valuesImpact of Acquisition Geometry and Patient Habitus on Lesion Detectability in Whole-Body FDG-PET: A Channelized Hotelling Observer Study
Fakhri G, Holdsworth C, Badawi R, Santos P, Moore S, Van den Abbeele A, Kijewski M. Impact of Acquisition Geometry and Patient Habitus on Lesion Detectability in Whole-Body FDG-PET: A Channelized Hotelling Observer Study. 2002, 3: 1402-1405. DOI: 10.1109/nssmic.2002.1239583.Peer-Reviewed Original ResearchBed positionChannelized Hotelling observer studyFDG-PET studiesAttenuation mapAcquisition modeMarginal detectionFDG-PETLesion detectionWhole-body FDG-PETHotelling observerScaling 2DTypical sizePatient sizeHours post-injectionPatient habitusAnatomical backgroundWhole bodyLesion sizeObservational studyPatientsLesionsLesion siteModePost-injectionAcquisition geometry