2024
Associations of Physical Activity Engagement with Cerebral Amyloid-β and Tau from Midlife
Gonzales M, Kojis D, Spartano N, Thibault E, DeCarli C, Fakhri G, Johnson K, Beiser A, Seshadri S. Associations of Physical Activity Engagement with Cerebral Amyloid-β and Tau from Midlife. Journal Of Alzheimer's Disease 2024, 100: 935-943. PMID: 39031362, DOI: 10.3233/jad-240322.Peer-Reviewed Original ResearchConceptsPhysical activity indexPhysical activity engagementAssociated with lower dementia riskPhysical activity index scoreAssociation of physical activityActive engagementPhysical activity levelsFramingham Heart StudyCross-sectional associationsCommunity-based cohortCardiovascular risk factorsDementia riskPhysical activityLifestyle interventionHeart StudyLinear regression modelsStratified analysisTau-PET retentionSelf-reportSex disparitiesActivity levelsLate lifeTau positron emission tomographyRisk factorsAge groupsAssociations of Plasma Tau with Amyloid and Tau PET: Results from the Community-Based Framingham Heart Study
Ramos-Cejudo J, Scott M, Tanner J, Pase M, McGrath E, Ghosh S, Osorio R, Thibault E, Fakhri G, Johnson K, Beiser A, Seshadri S. Associations of Plasma Tau with Amyloid and Tau PET: Results from the Community-Based Framingham Heart Study. Journal Of Alzheimer's Disease 2024, 100: 487-494. PMID: 38875034, DOI: 10.3233/jad-231320.Peer-Reviewed Original ResearchConceptsCommunity-based Framingham Heart StudyFramingham Heart StudyHeart StudyCross-sectional associationsPlasma total tauMiddle-aged participantsRisk of ADCognitively healthy individualsCommunity-basedCompound B (PiB)-PETMiddle-agedPositive associationPlasma tauParticipantsTau-PETAssociationTotal tau levelsAD brain pathologyTotal-tauHealthy individualsAPOEe4Tau levelsBurdenRhinal cortexPrecuneus regions
2023
Association of Sleep Duration and Change Over Time With Imaging Biomarkers of Cerebrovascular, Amyloid, Tau, and Neurodegenerative Pathology
Baril A, Kojis D, Himali J, Decarli C, Sanchez E, Johnson K, El Fakhri G, Thibault E, Yiallourou S, Himali D, Cavuoto M, Pase M, Beiser A, Seshadri S. Association of Sleep Duration and Change Over Time With Imaging Biomarkers of Cerebrovascular, Amyloid, Tau, and Neurodegenerative Pathology. Neurology 2023, 102: e207807. PMID: 38165370, PMCID: PMC10834132, DOI: 10.1212/wnl.0000000000207807.Peer-Reviewed Original ResearchConceptsHigher WMH burdenSelf-reported sleep durationLong sleep durationNeuroimaging metricsSleep durationAssociated with incident dementiaNeurodegenerative trajectoriesSleep duration categoriesNeuroimaging markersTAU outcomesIncident dementiaNeuroimagingSleep duration changesNeuroimaging testsLinear regression modelsDuration changesMRI metricsAlzheimer's diseaseAssociation of Pathologic and Volumetric Biomarker Changes With Cognitive Decline in Clinically Normal Adults
Hanseeuw B, Jacobs H, Schultz A, Buckley R, Farrell M, Guehl N, Becker J, Properzi M, Sanchez J, Quiroz Y, Vannini P, Sepulcre J, Yang H, Chhatwal J, Gatchel J, Marshall G, Amariglio R, Papp K, Rentz D, Normandin M, Price J, Healy B, El Fakhri G, Sperling R, Johnson K. Association of Pathologic and Volumetric Biomarker Changes With Cognitive Decline in Clinically Normal Adults. Neurology 2023, 101: e2533-e2544. PMID: 37968130, PMCID: PMC10791053, DOI: 10.1212/wnl.0000000000207962.Peer-Reviewed Original ResearchConceptsAssociated with cognitive declineOlder adultsNon-AD pathologyCognitive declineHippocampal volumeCognitive dataPreclinical Alzheimer Cognitive CompositeInferior temporal tauProspective cohort studyClinically normal older adultsHarvard Aging Brain StudyPittsburgh compound B PET scansOvert cognitive impairmentAnalyzed dataNormal older adultsAging Brain StudyClinically normal adultsLongitudinal associationsAlzheimer's diseaseCohort studyMemory impairmentCognitive compositeCognitive impairmentHippocampal atrophyCognitionAssociation of Novelty-Related Locus Coeruleus Function With Entorhinal Tau Deposition and Memory Decline in Preclinical Alzheimer Disease
Prokopiou P, Engels-Domínguez N, Schultz A, Sepulcre J, Koops E, Papp K, Marshall G, Normandin M, El Fakhri G, Rentz D, Sperling R, Johnson K, Jacobs H. Association of Novelty-Related Locus Coeruleus Function With Entorhinal Tau Deposition and Memory Decline in Preclinical Alzheimer Disease. Neurology 2023, 101: e1206-e1217. PMID: 37491329, PMCID: PMC10516269, DOI: 10.1212/wnl.0000000000207646.Peer-Reviewed Original ResearchConceptsLC activityMemory declineLocus coeruleusCognitive declineEC tauHarvard Aging Brain StudyHuman neuroimaging studiesSteeper memory declineNoradrenergic brainstem nucleiLongitudinal cognitive dataFunctional MRI dataTau depositionAging Brain StudyPreclinical Alzheimer's diseaseTau progressionCortical tau depositionElevated beta-amyloidInterventions promoting resilienceMild cognitive impairmentExecutive dysfunctionExecutive functionNeuroimaging studiesTau spreadingTemporal cortexCognitive compositeTau 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
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 controlsDisordersMGluR5
2019
Multi-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 imagingEvaluation 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 courseVisual cognition in non-amnestic Alzheimer's disease: Relations to tau, amyloid, and cortical atrophy
Putcha D, Brickhouse M, Touroutoglou A, Collins J, Quimby M, Wong B, Eldaief M, Schultz A, Fakhri G, Johnson K, Dickerson B, McGinnis S. Visual cognition in non-amnestic Alzheimer's disease: Relations to tau, amyloid, and cortical atrophy. NeuroImage Clinical 2019, 23: 101889. PMID: 31200149, PMCID: PMC6562373, DOI: 10.1016/j.nicl.2019.101889.Peer-Reviewed Original ResearchConceptsVisual cognitive testsNeuropsychological batteryAssociated with tauVariant of ADCortical atrophyCognitive testsLogopenic variant primary progressive aphasiaVariant primary progressive aphasiaMagnetic resonance imagingPrimary progressive aphasiaStructural magnetic resonance imagingVentral occipitotemporal cortexSuperior parietal cortexCognitive test performanceVisual cognitive dysfunctionCognitive task performanceNon-amnestic variantsSpatial patterns of tauAlzheimer's diseasePosterior cortical dysfunctionVisual cortical regionsOccipital association corticesAmyloid PETAmyloid-positive patientsPosterior cortical atrophyAutoradiography 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
Application of a Novel CD206+ Macrophage-Specific Arterial Imaging Strategy in HIV-Infected Individuals
Zanni M, Toribio M, Wilks M, Lu M, Burdo T, Walker J, Autissier P, Foldyna B, Stone L, Martin A, Cope F, Abbruzzese B, Brady T, Hoffmann U, Williams K, El-Fakhri G, Grinspoon S. Application of a Novel CD206+ Macrophage-Specific Arterial Imaging Strategy in HIV-Infected Individuals. The Journal Of Infectious Diseases 2017, 215: 1264-1269. PMID: 28204544, PMCID: PMC5853590, DOI: 10.1093/infdis/jix095.Peer-Reviewed Original ResearchMeSH KeywordsAortaAtherosclerosisCase-Control StudiesCross-Sectional StudiesDextransHIV InfectionsHumansLectins, C-TypeLymph NodesMacrophagesMaleMannansMannose ReceptorMannose-Binding LectinsMiddle AgedPlaque, AtheroscleroticRadiopharmaceuticalsReceptors, Cell SurfaceRegression AnalysisSingle Photon Emission Computed Tomography Computed TomographyTechnetium Tc 99m PentetateUnited StatesConceptsSingle-photon emission computed tomography/computed tomographyFirst-in-human dataNon-HIV-infected subjectsAortic plaque volumeHIV-infected subjectsHIV-infected individualsMacrophages ex vivoComputed tomographic angiographyCD206+ macrophagesTomography/computed tomographyTomographic angiographyImaging techniquesTechnetium TcHIV statusPlaque volumeCardiovascular diseaseHIVImaging strategiesCD206In vivo applicationsSubjectsTilmanoceptAngiographyMacrophagesTomography
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
2015
Synergistic role of simultaneous PET/MRI-MRS in soft tissue sarcoma metabolism imaging
Zhang X, Chen Y, Lim R, Huang C, Chebib I, Fakhri G. Synergistic role of simultaneous PET/MRI-MRS in soft tissue sarcoma metabolism imaging. Magnetic Resonance Imaging 2015, 34: 276-279. PMID: 26523656, PMCID: PMC4761342, DOI: 10.1016/j.mri.2015.10.027.Peer-Reviewed Original ResearchConceptsSoft tissue sarcomasMagnetic resonance imagingHigh (18)F-FDG uptakeT2 hyperintense massMagnetic resonance spectroscopyNeoadjuvant radiotherapyPathological resultsTumor marginsTissue sarcomasImaging findingsPET/MRI scansPET scansRight thighRadiotherapyNormal tissuesEmission tomographyResonance imagingMetabolite profilesSarcomaPET/MRIChemoRTChemoradiationSynergistic rolePETSurgeryPulmonary 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 field
2014
Relative role of motion and PSF compensation in whole‐body oncologic PET‐MR imaging
Petibon Y, Huang C, Ouyang J, Reese T, Li Q, Syrkina A, Chen Y, Fakhri G. Relative role of motion and PSF compensation in whole‐body oncologic PET‐MR imaging. Medical Physics 2014, 41: 042503. PMID: 24694156, PMCID: PMC3971824, DOI: 10.1118/1.4868458.Peer-Reviewed Original ResearchConceptsPoint spread function modelRespiratory motionPoint spread functionPET-MR scannersPencil-beam navigator echoesPET-MRMeasurement of respiratory motionPSF modelRespiratory motion correctionDetector blur effectsModel respiratory motionLung-liver interfacePatient studiesLesion contrastSimultaneous PET-MRSource of image degradationWhole-body PET imagingPET reconstruction algorithmMoving lesionsPhantom experiment resultsPET eventsContrast recoveryNavigator echoesIterative reconstruction processMotion correction
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
2011
Monitoring proton radiation therapy with in-room PET imaging
Zhu X, España S, Daartz J, Liebsch N, Ouyang J, Paganetti H, Bortfeld T, Fakhri G. Monitoring proton radiation therapy with in-room PET imaging. Physics In Medicine And Biology 2011, 56: 4041-4057. PMID: 21677366, PMCID: PMC3141290, DOI: 10.1088/0031-9155/56/13/019.Peer-Reviewed Original ResearchConceptsIn-room positron emission tomographyIn-roomProton therapy treatment roomPositron emission tomography systemProton range verificationSoft tissue-equivalent materialMonte Carlo predictionsTissue-equivalent materialsPositron emission tomography acquisition timesProton radiation therapyPositron emission tomographyBiological washoutRange verificationProton therapyList-modeActivity distribution patternsPhantom studyTreatment roomPET acquisitionSoft tissue regionsIn vivo verificationDeep-siteOff-line modalityPositron emission tomography dataAdenoid cystic carcinoma