2024
PET imaging of M4 muscarinic acetylcholine receptors in rhesus macaques using [11C]MK-6884: Quantification with kinetic modeling and receptor occupancy by CVL-231 (emraclidine), a novel positive allosteric modulator
Belov V, Guehl N, Duvvuri S, Iredale P, Moon S, Dhaynaut M, Chakilam S, MacDonagh A, Rice P, Yokell D, Renger J, Fakhri G, Normandin M. PET imaging of M4 muscarinic acetylcholine receptors in rhesus macaques using [11C]MK-6884: Quantification with kinetic modeling and receptor occupancy by CVL-231 (emraclidine), a novel positive allosteric modulator. Cerebrovascular And Brain Metabolism Reviews 2024, 44: 1329-1342. PMID: 38477292, PMCID: PMC11342722, DOI: 10.1177/0271678x241238820.Peer-Reviewed Original ResearchConceptsPositive allosteric modulatorsReceptor occupancyNon-human primatesBinding potentialPositron emission tomographyMuscarinic acetylcholine receptorsAllosteric modulatorsNon-human primate brainM4 muscarinic acetylcholine receptorStriatal hyperdopaminergiaAcetylcholine receptorsBrain regionsCaudate nucleusTotal volume of distributionDose-dependent blockReference regionVolume of distributionPositron emission tomography imagingEmission tomographyReceptor levelsFunction of dosePET scansClinical trialsBlood-basedRhesus macaques
2022
Simulation study of a 50 ps panel TOF PET imager
Pestotnik R, Razdevšek G, Dolenec R, Fakhri G, Križan P, Majewski S, Studen A, Korpar S. Simulation study of a 50 ps panel TOF PET imager. Journal Of Instrumentation 2022, 17: c12010. DOI: 10.1088/1748-0221/17/12/c12010.Peer-Reviewed Original ResearchPET scannerGamma detectorGamma raysTime-of-flight positron emission tomographyState-of-the-art clinical PET scannersGamma detection efficiencyClinical PET scannerImaging large objectsImproved time resolutionArtifact-free imagesDifferent phantomsDetector arrangementTime-of-flightBiograph VisionImage quality parametersDetection efficiencyTiming accuracyTime resolutionDetectorFWHMPositron emission tomographyReconstructed imagesRaysPositron emission tomography imagingMultichannel systemPET imaging studies to investigate functional expression of mGluR2 using [11C]mG2P001
Yuan G, Dhaynaut M, Guehl N, Neelamegam R, Moon S, Qu X, Poutiainen P, Afshar S, Fakhri G, Normandin M, Brownell A. PET imaging studies to investigate functional expression of mGluR2 using [11C]mG2P001. Cerebrovascular And Brain Metabolism Reviews 2022, 43: 296-308. PMID: 36172629, PMCID: PMC9903221, DOI: 10.1177/0271678x221130387.Peer-Reviewed Original ResearchConceptsPositive allosteric modulatorsPositron emission tomographyNon-human primatesMGluR2 positive allosteric modulatorPositron emission tomography imagingPositive allosteric modulator of mGluR2Metabotropic glutamate receptor 2Positron emission tomography imaging studiesExpression of mGluR2Glutamate receptor 2MGluR2 functionPsychiatric disordersMGluR2 expressionTissue glutamate concentrationMGluR2Expressing mGluR2Allosteric modulatorsRat brainTransfected CHO cellsReceptor 2Glutamate concentrationEmission tomographyImaging studiesPharmacological effectsImaging ligandsSynthesis and Characterization of 5‑(2-Fluoro-4‑[11C]methoxyphenyl)-2,2-dimethyl-3,4-dihydro‑2H‑pyrano[2,3‑b]pyridine-7-carboxamide as a PET Imaging Ligand for Metabotropic Glutamate Receptor 2
Yuan G, Dhaynaut M, Lan Y, Guehl N, Huynh D, Iyengar S, Afshar S, Jain M, Pickett J, Kang H, Wang H, Moon S, Ondrechen M, Wang C, Shoup T, Fakhri G, Normandin M, Brownell A. Synthesis and Characterization of 5‑(2-Fluoro-4‑[11C]methoxyphenyl)-2,2-dimethyl-3,4-dihydro‑2H‑pyrano[2,3‑b]pyridine-7-carboxamide as a PET Imaging Ligand for Metabotropic Glutamate Receptor 2. Journal Of Medicinal Chemistry 2022, 65: 2593-2609. PMID: 35089713, PMCID: PMC9434702, DOI: 10.1021/acs.jmedchem.1c02004.Peer-Reviewed Original ResearchConceptsNegative allosteric modulatorsMetabotropic glutamate receptor 2Positron emission tomographyGlutamate receptor 2MGluR2 functionNeuropsychiatric disordersDrug effectsBrain heterogeneityReceptor 2Allosteric modulatorsMGluR2Nonhuman primatesBrain imagingPositron emission tomography imagingPositron emission tomography imaging ligandsHigh molar activityEmission tomographyExcellent radiochemical purityImaging ligandsBlocking agentsPET imagingMolar activityTherapeutic targetMetabotropicDisorders
2020
MR‐based PET attenuation correction using a combined ultrashort echo time/multi‐echo Dixon acquisition
Han P, Horng D, Gong K, Petibon Y, Kim K, Li Q, Johnson K, Fakhri G, Ouyang J, Ma C. MR‐based PET attenuation correction using a combined ultrashort echo time/multi‐echo Dixon acquisition. Medical Physics 2020, 47: 3064-3077. PMID: 32279317, PMCID: PMC7375929, DOI: 10.1002/mp.14180.Peer-Reviewed Original ResearchConceptsLinear attenuation coefficientPositron emission tomography attenuation correctionPhysical compartmental modelAttenuation correctionShort T<sub>2</sub> componentPET attenuation correctionRadial k-space trajectoryMagnetic resonance (MR)-based methodK-space trajectoriesRadial trajectoryK-spaceAttenuation coefficientDixon acquisitionsPositron emission tomographyWhole white matterMuting methodImage reconstructionImaging speedMR signalMRAC methodPositron emission tomography imagingCorrectionGray matter regionsPhantomMatter regions
2017
Synthesis and preliminary PET imaging of 11C and 18F isotopologues of the ROS1/ALK inhibitor lorlatinib
Collier T, Normandin M, Stephenson N, Livni E, Liang S, Wooten D, Esfahani S, Stabin M, Mahmood U, Chen J, Wang W, Maresca K, Waterhouse R, El Fakhri G, Richardson P, Vasdev N. Synthesis and preliminary PET imaging of 11C and 18F isotopologues of the ROS1/ALK inhibitor lorlatinib. Nature Communications 2017, 8: 15761. PMID: 28594000, PMCID: PMC5472746, DOI: 10.1038/ncomms15761.Peer-Reviewed Original ResearchMeSH KeywordsAminopyridinesAnaplastic Lymphoma KinaseAnimalsCarbon RadioisotopesChemistry Techniques, SyntheticContrast MediaFluorine RadioisotopesHumansIsotope LabelingLactamsLactams, MacrocyclicMacaca mulattaMaleMicePositron-Emission TomographyProtein-Tyrosine KinasesProto-Oncogene ProteinsPyrazolesTissue DistributionXenograft Model Antitumor AssaysConceptsAnaplastic lymphoma kinasePositron emission tomographyPositron emission tomography imagingC-ros oncogene 1Non-small cell lung cancerCell lung cancerBrain tumor lesionsOptimal therapeutic outcomesLung cancer patientsBlood-brain barrierPF-06463922Clinical trial investigatorsTumor uptakeLung cancerSmall molecule inhibitorsCancer patientsTherapeutic outcomesLorlatinibEmission tomographyDosimetry assessmentNon-human primatesTrial investigatorsBrain permeabilityEarly goalRadiolabeling strategiesFeasibility study of using fall‐off gradients of early and late PET scans for proton range verification
Cho J, Grogg K, Min C, Zhu X, Paganetti H, Lee H, Fakhri G. Feasibility study of using fall‐off gradients of early and late PET scans for proton range verification. Medical Physics 2017, 44: 1734-1746. PMID: 28273345, PMCID: PMC5462437, DOI: 10.1002/mp.12191.Peer-Reviewed Original ResearchConceptsProton range verificationProton rangeMonte Carlo simulationsRange verificationFall-offIn-room positron emission tomographyCarlo simulationsResidual proton rangeDose fall-offPostirradiation delayPositron emission tomography imagingSOBP beamProton beamPositron emission tomographyPositron emission tomography scanPhantom studyIn-roomFunction of depthPhantomProtonOff-setMonteAcquisition timeBeamPositron emission tomography signal
2016
A novel approach to assess the treatment response using Gaussian random field in PET
Wang M, Guo N, Hu G, El Fakhri G, Zhang H, Li Q. A novel approach to assess the treatment response using Gaussian random field in PET. Medical Physics 2016, 43: 833-842. PMID: 26843244, PMCID: PMC4714995, DOI: 10.1118/1.4939879.Peer-Reviewed Original ResearchConceptsTherapy response assessmentStandardized uptake valuePositron emission tomographyEarly treatment responseResponse assessmentPositron emission tomography imagingTreatment responseTherapy responsePrediction of early treatment responseTreatment planningResponse to anticancer therapyTherapy response evaluationTumor-to-background contrastPost-therapy imagingClinical practiceEvaluate therapy responseReceiver operating characteristic curveDevelopment of personalized treatment plansEvaluate therapy effectsPersonalized treatment plansUptake valuePretherapy imagingClinical oncologyPatient managementAnticancer therapy
2014
MR‐based motion correction for PET imaging using wired active MR microcoils in simultaneous PET‐MR: Phantom study
Huang C, Ackerman J, Petibon Y, Brady T, Fakhri G, Ouyang J. MR‐based motion correction for PET imaging using wired active MR microcoils in simultaneous PET‐MR: Phantom study. Medical Physics 2014, 41: 041910. PMID: 24694141, PMCID: PMC3978416, DOI: 10.1118/1.4868457.Peer-Reviewed Original ResearchConceptsMotion correctionMR-based motion correctionStatic phantom dataPET quantitative accuracyPET-MRPET-MR scannersSimultaneous PET-MRHoffman phantomList-modePositron emission tomography imagingPET reconstructionBrain positron emission tomographyIterative PET reconstructionPhantom dataPhantomQuantitative accuracyIndependent noise realizationsImage contrastNoise realizationsHead motionPET dataPositron emission tomographyStatic referenceBrain PET scansMotion artifacts
2013
Determination of elemental tissue composition following proton treatment using positron emission tomography
Cho J, Ibbott G, Gillin M, Gonzalez-Lepera C, Min C, Zhu X, Fakhri G, Paganetti H, Mawlawi O. Determination of elemental tissue composition following proton treatment using positron emission tomography. Physics In Medicine And Biology 2013, 58: 3815-3835. PMID: 23681070, PMCID: PMC3763743, DOI: 10.1088/0031-9155/58/11/3815.Peer-Reviewed Original ResearchConceptsIn-room PET scannerProton treatmentSOBP beamPET scannerMonte Carlo simulationsTissue elemental compositionComposite decay curvePristine Bragg peakProton treatment planningIn-roomElemental tissue compositionCarlo simulationsDecay curvesRange verificationMonoenergetic beamsBeam rangeProton dosePhantom sectionsEmitted positronsPositron emission tomographyProton therapyBragg peakPhantom compositionDelivered dosePositron emission tomography imaging
2009
SU‐FF‐J‐129: In‐Room Proton Range Verification Using Mobile NeuroPET ‐ Feasibility Study
Knopf A, Zhu X, Parodi K, Paganetti H, Bortfeld T, Fakhri G. SU‐FF‐J‐129: In‐Room Proton Range Verification Using Mobile NeuroPET ‐ Feasibility Study. Medical Physics 2009, 36: 2506-2506. DOI: 10.1118/1.3181421.Peer-Reviewed Original ResearchProton range verificationRange verificationPET/CT scannerCommercial PET/CT scannersWater equivalent rangePositron emission tomographyBiological washoutPMMA phantomProton fieldsProton beamActivity depth profilesProton treatmentPhantom studyTreatment roomIn-roomPositron emission tomography scanPositron emission tomography dataPatient repositioningPhantomPositron emission tomography imagingProtonDepth profilesPET/CT imagingRadiation treatmentTotal dose
2008
Quantitative relationship between coronary vasodilator reserve assessed by 82Rb PET imaging and coronary artery stenosis severity
Anagnostopoulos C, Almonacid A, El Fakhri G, Curillova Z, Sitek A, Roughton M, Dorbala S, Popma J, Di Carli M. Quantitative relationship between coronary vasodilator reserve assessed by 82Rb PET imaging and coronary artery stenosis severity. European Journal Of Nuclear Medicine And Molecular Imaging 2008, 35: 1593-1601. PMID: 18425513, PMCID: PMC3124702, DOI: 10.1007/s00259-008-0793-2.Peer-Reviewed Original ResearchConceptsPositron emission tomographyCoronary artery diseaseCoronary vasodilator reserveMyocardial blood flowPositron emission tomography imagingPercent diameter stenosisDiameter stenosisEmission tomographyAge-matchedStenosis severityHyperaemic myocardial blood flowRisk factorsStress myocardial blood flowVasodilator reserveFunctional assessment of coronary artery diseaseAssessment of coronary artery diseaseClinically useful tool