2019
Real‐Time Imaging of Vaccine Biodistribution Using Zwitterionic NIR Nanoparticles
Katagiri W, Lee J, Tétrault M, Kang H, Jeong S, Evans C, Yokomizo S, Santos S, Jones C, Hu S, Fakhri G, Tsukada K, Choi H, Kashiwagi S. Real‐Time Imaging of Vaccine Biodistribution Using Zwitterionic NIR Nanoparticles. Advanced Healthcare Materials 2019, 8: e1900035. PMID: 31165556, PMCID: PMC6687515, DOI: 10.1002/adhm.201900035.Peer-Reviewed Original ResearchConceptsNIR fluorescence imaging systemLymph nodesVaccine antigensClinical vaccine candidatesOptimization of vaccine designFluorescence imaging systemAntigen presenting cellsInduce protective immune responsesSecondary lymphoid tissuesDelivery of vaccine antigensProtective immune responsesZwitterionic NIR fluorophoreFlow cytometry analysisPresenting cellsLymphoid tissueIntradermal administrationAdverse reactionsBioconjugate vaccineImmune responseVaccine designVaccine candidatesModel vaccineCytometry analysisZwitterionic fluorophoresAntigen
2016
Validation of Bayesian analysis of compartmental kinetic models in medical imaging
Sitek A, Li Q, Fakhri G, Alpert N. Validation of Bayesian analysis of compartmental kinetic models in medical imaging. Physica Medica 2016, 32: 1252-1258. PMID: 27692754, PMCID: PMC5720163, DOI: 10.1016/j.ejmp.2016.09.010.Peer-Reviewed Original ResearchConceptsAccurate estimation of uncertaintyComputer simulationsMedical imagesPosterior distributionDistributed noiseTime series of imagesClosed-formSeries of imagesData setsKinetic parametersMarkov chain Monte Carlo methodsPosterior distributions of kinetic parametersNon-linear least squares methodAccurate estimationComputerLeast-squares methodKinetic modelEstimation of kinetic parametersF18-fluorodeoxyglucoseBayesian estimationImagesStatistical inferenceMonte Carlo methodEstimates of uncertaintyInformationPharmacokinetic Evaluation of the Tau PET Radiotracer 18F-T807 (18F-AV-1451) in Human Subjects
Wooten D, Guehl N, Verwer E, Shoup T, Yokell D, Zubcevik N, Vasdev N, Zafonte R, Johnson K, Fakhri G, Normandin M. Pharmacokinetic Evaluation of the Tau PET Radiotracer 18F-T807 (18F-AV-1451) in Human Subjects. Journal Of Nuclear Medicine 2016, 58: 484-491. PMID: 27660144, PMCID: PMC5334185, DOI: 10.2967/jnumed.115.170910.Peer-Reviewed Original ResearchConceptsDistribution volume ratioTraumatic brain injuryMetabolite-corrected arterial input functionPET imagingPlasma radioactivity concentrationsTemporal cortexDynamic PET imagesTotal volume of distributionVolume of distributionTraumatic brain injury subjectsMesial temporal cortexArterial blood samplesPosterior cingulate gyrusFocal uptakeSUV ratioHuman subjectsArterial input functionPosterior corpus callosumBolus injectionPharmacokinetic evaluation
2015
Pulmonary imaging using respiratory motion compensated simultaneous PET/MR
Dutta J, Huang C, Li Q, El Fakhri G. Pulmonary imaging using respiratory motion compensated simultaneous PET/MR. Medical Physics 2015, 42: 4227-4240. PMID: 26133621, PMCID: PMC4474958, DOI: 10.1118/1.4921616.Peer-Reviewed Original ResearchConceptsRespiratory motionContrast-to-noise ratioClinical patient studiesPulse sequenceHigh-intensity featuresXCAT studyLow proton densityXCAT simulationPatient studiesXCAT phantomAttenuation mapBiograph mMRComplete data acquisitionSimultaneous PET/MRNonrigid registrationPET/MR scannersPET/magnetic resonanceMagnetic susceptibilityProton densityQuantitative accuracyRelaxation timePulmonary imagingLung lesionsBlurring artifactsDeformation fieldA Spectral Graph Regression Model for Learning Brain Connectivity of Alzheimer’s Disease
Hu C, Cheng L, Sepulcre J, Johnson K, Fakhri G, Lu Y, Li Q. A Spectral Graph Regression Model for Learning Brain Connectivity of Alzheimer’s Disease. PLOS ONE 2015, 10: e0128136. PMID: 26024224, PMCID: PMC4449104, DOI: 10.1371/journal.pone.0128136.Peer-Reviewed Original ResearchConceptsNetwork featuresAlzheimer's diseaseConsistent with known pathologyUnknown graphConnection weightsReconstruction networkCortical hubsDegree statisticsData modelSmooth signalsFeatures of brain pathologyOptimization frameworkAmyloid-bPartial correlation estimationImage dataNetworkGraphGlobal connectivity measuresPositron emission tomographyConnectivity measuresNeurodegenerative diseasesConnectivity patternsSample correlationClinical ADSimulated data
2014
4D 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 approach
2013
Dual-Tracer PET Using Generalized Factor Analysis of Dynamic Sequences
El Fakhri G, Trott C, Sitek A, Bonab A, Alpert N. Dual-Tracer PET Using Generalized Factor Analysis of Dynamic Sequences. Molecular Imaging And Biology 2013, 15: 666-674. PMID: 23636489, PMCID: PMC3812387, DOI: 10.1007/s11307-013-0631-1.Peer-Reviewed Original ResearchConceptsEmit gamma raysPositron emission tomographyNear-simultaneous imagingSingle-photon emissionBrain PET studiesGamma raysSingle-photon emission computed tomographyActivity distributionRaclopride studiesEmission computed tomographyPositron emission tomography radiopharmaceuticalsSimultaneous imagingD2 bindingFactor analysis of dynamic sequencesActivity estimationTime activity curvesRacloprideFDGRhesus monkeysEmission tomographyPET studiesActivation curveBrain metabolismEmissionSimulate human data
2012
Single‐scan rest/stress imaging 18F‐labeled flow tracers
Alpert N, Fang Y, Fakhri G. Single‐scan rest/stress imaging 18F‐labeled flow tracers. Medical Physics 2012, 39: 6609-6620. PMID: 23127055, PMCID: PMC3482258, DOI: 10.1118/1.4754585.Peer-Reviewed Original Research
2009
Monte Carlo modeling of cascade gamma rays in 86Y PET imaging: preliminary results
Zhu X, Fakhri G. Monte Carlo modeling of cascade gamma rays in 86Y PET imaging: preliminary results. Physics In Medicine And Biology 2009, 54: 4181-4193. PMID: 19521011, PMCID: PMC3111055, DOI: 10.1088/0031-9155/54/13/014.Peer-Reviewed Original ResearchConceptsCascade gamma raysScatter fractionGamma raysPhoton energy distributionLow count ratesHigh-energy photonsMonte Carlo programScatter correction methodGATE simulation packageMonte Carlo modelDevelopment of correction methodsSpatial resolutionGamma photonsEnergy windowCount rateScattering eventsRandom coincidencesEnergy distributionPhantom acquisitionsPersonal dosimetryPET imagingVariance reduction techniquesPhotonsCorrection methodSimSET
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 head
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
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 windowTaskClinicMonte