2022
Manifold Learning via Linear Tangent Space Alignment (LTSA) for Accelerated Dynamic MRI With Sparse Sampling
Djebra Y, Marin T, Han P, Bloch I, Fakhri G, Ma C. Manifold Learning via Linear Tangent Space Alignment (LTSA) for Accelerated Dynamic MRI With Sparse Sampling. IEEE Transactions On Medical Imaging 2022, 42: 158-169. PMID: 36121938, PMCID: PMC10024645, DOI: 10.1109/tmi.2022.3207774.Peer-Reviewed Original ResearchMeSH KeywordsAlgorithmsComputer SimulationImage Processing, Computer-AssistedMagnetic Resonance ImagingModels, TheoreticalConceptsSpace alignmentSampled k-space dataState-of-the-art methodsIntrinsic low-dimensional manifold structureNumerical simulation studyLow-dimensional manifold structureState-of-the-artLinear subspace modelSparsity modelModel-based frameworkSubspace modelManifold structureMathematical modelManifold modelSparse samplingImage reconstructionMRI applicationsDynamic magnetic resonance imagingSpatiotemporal signalsSpatial resolutionPerformanceSimulation studyImagesMethodSparsity
2019
Evaluation of pharmacokinetic modeling strategies for in-vivo quantification of tau with the radiotracer [18F]MK6240 in human subjects
Guehl N, Wooten D, Yokell D, Moon S, Dhaynaut M, Katz S, Moody K, Gharagouzloo C, Kas A, Johnson K, El Fakhri G, Normandin M. Evaluation of pharmacokinetic modeling strategies for in-vivo quantification of tau with the radiotracer [18F]MK6240 in human subjects. European Journal Of Nuclear Medicine And Molecular Imaging 2019, 46: 2099-2111. PMID: 31332496, PMCID: PMC6709592, DOI: 10.1007/s00259-019-04419-z.Peer-Reviewed Original ResearchConceptsReference tissue methodDistribution volume ratioTissue methodIn vivo quantificationPharmacokinetic modeling strategiesArterial plasma input functionMultilinear reference tissue methodsTwo-tissue compartment modelBlood:plasma ratioTissue-to-plasmaPlasma input functionPlasma concentration time courseBlood-based methodMethodsThirty-five subjectsSUV ratioBlood-based analysesData setsArterial input functionPET scansControl subjectsMild cognitive impairmentPlasma ratioRadiometabolite analysisHealthy controlsConcentration time course
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
2015
Matched signal detection on graphs: Theory and application to brain imaging data classification
Hu C, Sepulcre J, Johnson K, Fakhri G, Lu Y, Li Q. Matched signal detection on graphs: Theory and application to brain imaging data classification. NeuroImage 2015, 125: 587-600. PMID: 26481679, DOI: 10.1016/j.neuroimage.2015.10.026.Peer-Reviewed Original ResearchConceptsImage data classificationWeighted energy detectorGraph-signalGraph Laplacian eigenvaluesEnergy detectorManifold structureProblem of Alzheimer's diseaseData classificationGraph LaplacianSubspace detectorWeighted graphMSD approachSignal processingSignal detectionIntrinsic structureLaplacian eigenvaluesSubspaceTest statisticsGraphRandom signalsData setsLowest eigenvalueGaussian distributionTraditional methodsEigenvalues
2014
Effect 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 methodDetection
2013
Clinical impact of time-of-flight and point response modeling in PET reconstructions: a lesion detection study
Schaefferkoetter J, Casey M, Townsend D, Fakhri G. Clinical impact of time-of-flight and point response modeling in PET reconstructions: a lesion detection study. Physics In Medicine And Biology 2013, 58: 1465-1478. PMID: 23403399, PMCID: PMC3616316, DOI: 10.1088/0031-9155/58/5/1465.Peer-Reviewed Original ResearchMeSH KeywordsHumansImage Processing, Computer-AssistedModels, TheoreticalNeoplasmsObserver VariationPositron-Emission TomographyTime FactorsConceptsPoint spread functionTime-of-flightBenefit of TOFPET reconstructionNumerical modelOptimal reconstruction parametersLocalization receiver operating characteristicsLesion-detection studiesObserved SNRReconstruction schemeSpread functionReconstruction parametersPerformanceNumerical observationsPatient images