2024
Investigating muscle coordination patterns with Granger causality analysis in protrusive motion from tagged and diffusion MRI
Park H, Xing F, Stone M, Kang H, Liu X, Zhuo J, Fels S, Reese T, Wedeen V, Fakhri G, Prince J, Woo J. Investigating muscle coordination patterns with Granger causality analysis in protrusive motion from tagged and diffusion MRI. JASA Express Letters 2024, 4: 095201. PMID: 39240196, PMCID: PMC11384280, DOI: 10.1121/10.0028500.Peer-Reviewed Original ResearchAccelerated 3D metabolite T1 mapping of the brain using variable‐flip‐angle SPICE
Zhao Y, Li Y, Guo R, Jin W, Sutton B, Ma C, Fakhri G, Li Y, Luo J, Liang Z. Accelerated 3D metabolite T1 mapping of the brain using variable‐flip‐angle SPICE. Magnetic Resonance In Medicine 2024, 92: 1310-1322. PMID: 38923032, DOI: 10.1002/mrm.30200.Peer-Reviewed Original ResearchConceptsLow-rank tensor modelGeneralized series modelMetabolite TExperimental resultsBrain metabolitesClinically acceptable scan timeEfficient encodingPhantom experimental resultsAcceptable scan timeNoisy dataSparse samplingImaging problemsData processingHealthy subject dataVariable flip angleFlip angleTensor modelSaturation effectsQuantitative metabolic imagingMRSI techniquePhantomScan timeData acquisitionMetabolic imagingT1 mapping
2023
Longitudinal Imaging in a Patient With Opioid-associated Amnestic Syndrome
Barash J, Schmahmann J, Xie Z, Lev M, Fakhri G. Longitudinal Imaging in a Patient With Opioid-associated Amnestic Syndrome. Cognitive And Behavioral Neurology 2023, 36: 194-197. PMID: 37389894, PMCID: PMC10527331, DOI: 10.1097/wnn.0000000000000347.Peer-Reviewed Original ResearchConceptsOpioid-associated amnestic syndromeFluid-attenuated inversion recoveryPositron emission tomographyAmnestic syndromeHistory of attention-deficit hyperactivity disorderAttention-deficit hyperactivity disorderBrain regions of individualsSubstance use disordersOpioid misuseMild memory lossN-acetyl aspartate/creatineUrine toxicology screenFollow-up imagingHistory of opioid misuseRegions of individualsTau depositionTau positron emission tomographyHyperactivity disorderIntravenous heroinRight hippocampusAnterograde amnesiaRestricted diffusionBrain regionsHippocampal abnormalitiesLongitudinal imagingTau Positron Emission Tomography and Neurocognitive Function Among Former Professional American-Style Football Players
Dhaynaut M, Grashow R, Normandin M, Wu O, Marengi D, Terry D, Sanchez J, Weisskopf M, Speizer F, Taylor H, Guehl N, Seshadri S, Beiser A, Daneshvar D, Johnson K, Iverson G, Zafonte R, Fakhri G, Baggish A. Tau Positron Emission Tomography and Neurocognitive Function Among Former Professional American-Style Football Players. Journal Of Neurotrauma 2023, 40: 1614-1624. PMID: 37282582, PMCID: PMC10458363, DOI: 10.1089/neu.2022.0454.Peer-Reviewed Original ResearchConceptsPositron emission tomographyDistribution volume ratioNeuropsychological testsNeurocognitive functionStandardized uptake value ratioControl participantsMeasures of neurocognitive functionStructural magnetic resonance imagingMeasures of memoryDepressive symptom severityMale control participantsEmission tomographyCerebellar gray matterNeuropsychological measuresTau positron emission tomographyExecutive functionSymptom severityBrain regionsEntorhinal cortexRepetitive head impactsP-tauReference regionFormer playersRepetitive head impact exposureMale controls
2022
A multi-pronged investigation of option generation using depression, PET and modafinil
Ang Y, Cusin C, Petibon Y, Dillon D, Breiger M, Belleau E, Normandin M, Schroder H, Boyden S, Hayden E, Levine M, Jahan A, Meyer A, Kang M, Brunner D, Gelda S, Hooker J, Fakhri G, Fava M, Pizzagalli D. A multi-pronged investigation of option generation using depression, PET and modafinil. Brain 2022, 145: 1854-1865. PMID: 35150243, PMCID: PMC9166534, DOI: 10.1093/brain/awab429.Peer-Reviewed Original ResearchConceptsD2/D3 receptor availabilitySelf-generated optionsDepressive disorderDepressed individualsReceptor availabilityDopamine D2/D3 receptor availabilityNon-depressed adultsEffects of modafinilPutamen of patientsAssociated with uniquenessOption generationD2/D3 receptorsDopaminergic activityClinical depressionBinding potentialModafinilHealthy participantsPutamenPlacebo-controlledSamples of healthy peopleDouble-blindDisordersSelf-generationHealthy controlsDopamine
2021
In vivo imaging of mGlu5 receptor expression in humans with Fragile X Syndrome towards development of a potential biomarker
Mody M, Petibon Y, Han P, Kuruppu D, Ma C, Yokell D, Neelamegam R, Normandin M, Fakhri G, Brownell A. In vivo imaging of mGlu5 receptor expression in humans with Fragile X Syndrome towards development of a potential biomarker. Scientific Reports 2021, 11: 15897. PMID: 34354107, PMCID: PMC8342610, DOI: 10.1038/s41598-021-94967-y.Peer-Reviewed Original ResearchConceptsFragile X syndromeFragile X mental retardation proteinX syndromeLoss of fragile X mental retardation proteinMGlu5 receptor expressionMetabotropic glutamate subtype 5 receptorsDrug occupancy studiesSignificant group differencesFragile X mental retardationHealthy controlsAnterior cingulateMGluR5 availabilityVisuospatial processingMGlu5 receptorsOlfactory cortexBrain areasGroup differencesRetardation proteinGlutamate signalingImages of maleNeurodevelopmental disordersExcessive glutamate signalingGender-matched controlsDisordersMGluR5The cortical origin and initial spread of medial temporal tauopathy in Alzheimer’s disease assessed with positron emission tomography
Sanchez J, Becker J, Jacobs H, Hanseeuw B, Jiang S, Schultz A, Properzi M, Katz S, Beiser A, Satizabal C, O'Donnell A, DeCarli C, Killiany R, El Fakhri G, Normandin M, Gómez-Isla T, Quiroz Y, Rentz D, Sperling R, Seshadri S, Augustinack J, Price J, Johnson K. The cortical origin and initial spread of medial temporal tauopathy in Alzheimer’s disease assessed with positron emission tomography. Science Translational Medicine 2021, 13 PMID: 33472953, PMCID: PMC7978042, DOI: 10.1126/scitranslmed.abc0655.Peer-Reviewed Original ResearchConceptsPositron emission tomographyTemporal lobeMedial temporal lobe tauAlzheimer's diseaseMedial temporal lobeStudy of normal agingAssociated with baseline measuresMolecular positron emission tomographyTau-PET signalDegree of clinical impairmentEmission tomographyModel of Alzheimer's diseaseTemporal lobe anatomyCognitive declineClinical impairmentNormal agingAdult participantsStudy of AgingRhinal sulcusBrain pathologyExtratemporal regionsPET measurementsLongitudinal studyTau progressionClinically normal people
2019
Assessment of Striatal Dopamine Transporter Binding in Individuals With Major Depressive Disorder
Pizzagalli D, Berretta S, Wooten D, Goer F, Pilobello K, Kumar P, Murray L, Beltzer M, Boyer-Boiteau A, Alpert N, Fakhri G, Mechawar N, Vitaliano G, Turecki G, Normandin M. Assessment of Striatal Dopamine Transporter Binding in Individuals With Major Depressive Disorder. JAMA Psychiatry 2019, 76: 854-861. PMID: 31042280, PMCID: PMC6495358, DOI: 10.1001/jamapsychiatry.2019.0801.Peer-Reviewed Original ResearchConceptsMajor depressive disorderDA transporter availabilityVentral tegmental areaDA transporterDAT availabilityTegmental areaDepressive disorderDA signalingPositron emission tomographyDAT expressionMcLean HospitalHealthy controlsMajor depressive disorder groupsNumbers of depressive episodesStriatal dopamine transporter bindingDA transporter levelsLevels of DAT expressionStriatal DAT expressionStriatal DAT availabilityDA transporter densityDAT binding potentialDopamine transporter bindingOlder healthy controlsMesolimbic pathwayDA clearanceMulti-Modal Signatures of Tau Pathology, Neuronal Fiber Integrity, and Functional Connectivity in Traumatic Brain Injury
Wooten D, Ortiz-Terán L, Zubcevik N, Zhang X, Huang C, Sepulcre J, Atassi N, Johnson K, Zafonte R, Fakhri G. Multi-Modal Signatures of Tau Pathology, Neuronal Fiber Integrity, and Functional Connectivity in Traumatic Brain Injury. Journal Of Neurotrauma 2019, 36: 3233-3243. PMID: 31210098, PMCID: PMC6857466, DOI: 10.1089/neu.2018.6178.Peer-Reviewed Original ResearchConceptsTraumatic brain injuryTraumatic brain injury subjectsDistribution volume ratioWhite matter integrityFunctional connectivityDiffusion tensor imagingPositron emission tomographyTBI subjectsResting-state functional magnetic resonance imagingResting state functional connectivityFunctional magnetic resonance imagingFractional anisotropyDecreased white matter integrityGroup of TBI subjectsIncreased functional connectivityFunctional MRI resultsGraph theory metricsBrain injuryLiving human brainMagnetic resonance imagingNoninvasive neuroimaging techniquesBrain regionsFunctional MRINeuroimaging techniquesDiffusion tractography imagingAutoradiography validation of novel tau PET tracer [F-18]-MK-6240 on human postmortem brain tissue
Aguero C, Dhaynaut M, Normandin M, Amaral A, Guehl N, Neelamegam R, Marquie M, Johnson K, El Fakhri G, Frosch M, Gomez-Isla T. Autoradiography validation of novel tau PET tracer [F-18]-MK-6240 on human postmortem brain tissue. Acta Neuropathologica Communications 2019, 7: 37. PMID: 30857558, PMCID: PMC6410510, DOI: 10.1186/s40478-019-0686-6.Peer-Reviewed Original ResearchConceptsIn vivo detection of neurofibrillary tanglesNeurofibrillary tanglesDetection of neurofibrillary tanglesAlzheimer's diseaseTDP-43Binds to neurofibrillary tanglesFrontotemporal lobar degeneration-tauOff-target bindingDNA-binding protein 43Binding patternsNon-Alzheimer tauopathiesHuman postmortem brain tissueTau aggregationPostmortem brain tissueBinding signalBinding targetsCerebral amyloid angiopathyIn vivo detectionB-amyloidNeurodegenerative diseasesHuman brain tissueTauTau positron emission tomographyBindingMK-6240
2018
Magnetic resonance imaging based anatomical assessment of tongue impairment due to amyotrophic lateral sclerosis: A preliminary study
Lee E, Xing F, Ahn S, Reese T, Wang R, Green J, Atassi N, Wedeen V, El Fakhri G, Woo J. Magnetic resonance imaging based anatomical assessment of tongue impairment due to amyotrophic lateral sclerosis: A preliminary study. The Journal Of The Acoustical Society Of America 2018, 143: el248-el254. PMID: 29716267, PMCID: PMC5895467, DOI: 10.1121/1.5030134.Peer-Reviewed Original ResearchConceptsDiffusion tensor imagingHigh-resolution magnetic resonance imagingMagnetic resonance imagingResonance imagingEffects of amyotrophic lateral sclerosisAmyotrophic lateral sclerosisTensor imagingAmyotrophic lateral sclerosis patientsFiber connectionsSpeechNeurological disordersLateral sclerosis
2017
Frontostriatal and Dopamine Markers of Individual Differences in Reinforcement Learning: A Multi-modal Investigation
Kaiser R, Treadway M, Wooten D, Kumar P, Goer F, Murray L, Beltzer M, Pechtel P, Whitton A, Cohen A, Alpert N, Fakhri G, Normandin M, Pizzagalli D. Frontostriatal and Dopamine Markers of Individual Differences in Reinforcement Learning: A Multi-modal Investigation. Cerebral Cortex 2017, 28: 4281-4290. PMID: 29121332, PMCID: PMC6454484, DOI: 10.1093/cercor/bhx281.Peer-Reviewed Original ResearchConceptsDA transporterRL behaviourVentral striatumDA clearanceFunctional connectivityBinding potentialLevel of neurocognitive functioningIncreased intrinsic functional connectivityMulti-modal neuroimaging studiesResting-state functional connectivityPhasic DA activityStriatal DA transporterIntrinsic functional connectivityReinforcement learning behaviorMulti-modal investigationsFrontostriatal circuitsFrontostriatal connectivityFrontostriatal regionsOrbitofrontal cortexDA activityNeuroimaging studiesOrbitofrontal regionsDopamine markersNeurocognitive functionDopamine
2016
Pharmacokinetic 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
2014
First Human Use of a Radiopharmaceutical Prepared by Continuous-Flow Microfluidic Radiofluorination: Proof of Concept with the Tau Imaging Agent [18F]T807
Liang S, Yokell D, Normandin M, Rice P, Jackson R, Shoup T, Brady T, Fakhri G, Collier T, Vasdev N. First Human Use of a Radiopharmaceutical Prepared by Continuous-Flow Microfluidic Radiofluorination: Proof of Concept with the Tau Imaging Agent [18F]T807. Molecular Imaging 2014, 13: 7290.2014.00025. PMID: 25248283, DOI: 10.2310/7290.2014.00025.Peer-Reviewed Original Research
2013
Clinical Application of In-Room Positron Emission Tomography for In Vivo Treatment Monitoring in Proton Radiation Therapy
Min C, Zhu X, Winey B, Grogg K, Testa M, Fakhri G, Bortfeld T, Paganetti H, Shih H. Clinical Application of In-Room Positron Emission Tomography for In Vivo Treatment Monitoring in Proton Radiation Therapy. International Journal Of Radiation Oncology • Biology • Physics 2013, 86: 183-189. PMID: 23391817, PMCID: PMC3640852, DOI: 10.1016/j.ijrobp.2012.12.010.Peer-Reviewed Original ResearchConceptsIn-room positron emission tomographyProton therapyIn-roomPositron emission tomography scanIn-room PET scannerPassive scattering proton therapyShapes of target volumesPositron emission tomographyMC predictionBeam range uncertaintiesMeasured PET imagesMonte CarloProton radiation therapyLocal elemental compositionBiological washoutScan timeTreatment headTreatment verificationRange uncertaintiesTarget volumePET scan timePET scannerPET systemComputed tomographyMC results
2012
Parametric imaging with Bayesian priors: A validation study with 11C-Altropane PET
Fang Y, Fakhri G, Becker J, Alpert N. Parametric imaging with Bayesian priors: A validation study with 11C-Altropane PET. NeuroImage 2012, 61: 131-138. PMID: 22425668, DOI: 10.1016/j.neuroimage.2012.03.003.Peer-Reviewed Original ResearchMeSH KeywordsAdolescentAdultAlgorithmsBayes TheoremBiasCarbon RadioisotopesCocaineData Interpretation, StatisticalFemaleHumansImage Processing, Computer-AssistedKineticsLeast-Squares AnalysisMaleMiddle AgedNeuroimagingNonlinear DynamicsNormal DistributionPopulationPositron-Emission TomographyRadiopharmaceuticalsReference ValuesSample SizeYoung Adult
2005
Quantitative dynamic cardiac 82Rb PET using generalized factor and compartment analyses.
El Fakhri G, Sitek A, Guérin B, Kijewski M, Di Carli M, Moore S. Quantitative dynamic cardiac 82Rb PET using generalized factor and compartment analyses. Journal Of Nuclear Medicine 2005, 46: 1264-71. PMID: 16085581.Peer-Reviewed Original ResearchMeSH KeywordsAdultAgedAged, 80 and overAlgorithmsComputer SimulationCoronary Artery DiseaseFeasibility StudiesFemaleHeartHumansImage Interpretation, Computer-AssistedMaleMiddle AgedModels, CardiovascularPositron-Emission TomographyRadiopharmaceuticalsReproducibility of ResultsRubidium RadioisotopesSensitivity and SpecificitySeverity of Illness IndexConceptsMyocardial perfusionAbsolute myocardial perfusionCatheterization resultsMyocardial tissue extractsDipyridamole stressCardiac PETClinical valueMyocardial factorsFactor analysis of dynamic sequencesPatient studiesLVNoninvasive estimationAccurate input functionPatientsCompartment analysisAverage errorPerfusionParametric mappingTissue extractsRV contributionRV
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