2021
Deep learning-based GTV contouring modeling inter- and intra- observer variability in sarcomas
Marin T, Zhuo Y, Lahoud R, Tian F, Ma X, Xing F, Moteabbed M, Liu X, Grogg K, Shusharina N, Woo J, Lim R, Ma C, Chen Y, El Fakhri G. Deep learning-based GTV contouring modeling inter- and intra- observer variability in sarcomas. Radiotherapy And Oncology 2021, 167: 269-276. PMID: 34808228, PMCID: PMC8934266, DOI: 10.1016/j.radonc.2021.09.034.Peer-Reviewed Original ResearchConceptsGross tumor volumeRadiation therapy treatment planningGross tumor volume contoursGross tumor volume delineationTherapy treatment planningIntra-observer variabilityConsensus contoursGTV contoursPre-operative CT imagesSoft tissue sarcomasRadiation oncologistsTumor volumeBone sarcomasTreatment planningAccurate contoursCT imagesDelineation procedureSarcomaSoft tissueConfidence levelRadiationPatientsHausdorff distanceMultiple contoursX-ray
2017
Guest Editorial Low-Dose CT: What Has Been Done, and What Challenges Remain?
Liang J, La Riviere P, Fakhri G, Glick S, Siewerdsen J. Guest Editorial Low-Dose CT: What Has Been Done, and What Challenges Remain? IEEE Transactions On Medical Imaging 2017, 36: 2409-2416. DOI: 10.1109/tmi.2017.2768978.Peer-Reviewed Original ResearchCone-beam CTMulti-detector row CTDiscovery of X-raysIntroduction of computed tomographyMonitoring of therapeutic responseMulti-detector-rowImage-guided interventionsProjection dataMagnetic resonance imagingPositron emission tomographyTherapeutic responseEmergency examinationTreatment planningVolumetric imagesDiagnostic imagingEmission tomographyImaging modalitiesResonance imagingX-rayMedical imaging modalitiesCTTomographyTomographic imagesPositronMulti-Materials Decomposition using clinical Dualenergy CT
Zhao T, Kim K, Wu D, Kalra M, Fakhri G, Li Q. Multi-Materials Decomposition using clinical Dualenergy CT. 2017, 00: 1-4. DOI: 10.1109/nssmic.2017.8532936.Peer-Reviewed Original ResearchAttenuation coefficient functionDecomposition methodMulti-materials decomposition methodDomain decompositionMulti-materialAttenuation coefficientMaterial informationScanned objectX-ray sourcesMaterialsX-rayMedical applicationsEffective attenuation coefficientCoefficient functionsDecompositionMulti-material decompositionCoefficientDensity-based clustering
2014
Sparse-View Spectral CT Reconstruction Using Spectral Patch-Based Low-Rank Penalty
Kim K, Ye J, Worstell W, Ouyang J, Rakvongthai Y, Fakhri G, Li Q. Sparse-View Spectral CT Reconstruction Using Spectral Patch-Based Low-Rank Penalty. IEEE Transactions On Medical Imaging 2014, 34: 748-760. PMID: 25532170, DOI: 10.1109/tmi.2014.2380993.Peer-Reviewed Original ResearchConceptsLow-rank penaltySelf-similarity of patchesLog-likelihoodPoisson log-likelihoodCost functionSpectral CT reconstructionOriginal cost functionGPU implementationAlternating minimizationSensitive to intensity changesConventional algorithmsSpectral imagingEdge directionComputational costProcedure algorithmComputational advantagesAlgorithmX-ray transmissionComputer simulationsOptimization methodSpectral computed tomographySelf-similarityCT reconstructionX-rayGPUSpectral CT Using Multiple Balanced K-Edge Filters
Rakvongthai Y, Worstell W, Fakhri G, Bian J, Lorsakul A, Ouyang J. Spectral CT Using Multiple Balanced K-Edge Filters. IEEE Transactions On Medical Imaging 2014, 34: 740-747. PMID: 25252276, PMCID: PMC4349342, DOI: 10.1109/tmi.2014.2358561.Peer-Reviewed Original ResearchConceptsK-edge filtersReconstructed attenuation coefficientsEnergy binsAttenuation coefficientMultiple energy binsX-ray sourcesX-ray tubeBack-projection reconstructionSpectral CT imagingTransmission matrixModel expectationsSinogram binsBeam hardeningComplex phantomsSpectral computed tomographyK-edgeAttenuation imagesSpectral CTCT scannerX-rayConventional detectorsBack-projectionSinogramPhantomCost-effective system design
2003
The Effects of Compensation for Scatter, Lead X-Rays, and High-Energy Contamination on Tumor Detectability and Activity Estimation in Ga-67 Imaging
Fakhri G, Kijewski M, Maksud P, Moore S. The Effects of Compensation for Scatter, Lead X-Rays, and High-Energy Contamination on Tumor Detectability and Activity Estimation in Ga-67 Imaging. IEEE Transactions On Nuclear Science 2003, 50: 439. DOI: 10.1109/tns.2003.812446.Peer-Reviewed Original ResearchLead X-raysHigh-energy contaminationPresence of scatteringOptimal energy windowSignal-to-noise ratioAnthropomorphic torso phantomHigh-energy photonsMonte Carlo programGa-67 imagingSpherical tumorCompton scatteringPhoton interactionsEnergy windowScattered photonsEnergy photonsPhotopeak windowTorso phantomActivity estimationHigh energyFactors affecting image qualityX-rayScatter correctionPhotopeakGa-67PhotonsQuantitative Ga-67 SPECT Imaging
Moore S, Fakhri G, Park I, Kijewski M. Quantitative Ga-67 SPECT Imaging. 2003, 4: 2898-2900. DOI: 10.1109/nssmic.2003.1352489.Peer-Reviewed Original ResearchPb X-raysContaminating photonsPatient scatterUnscattered photonsAnthropomorphic phantomPhotopeak windowNonuniform attenuationCollimator resolutionAttenuation mapGa-67Iterative reconstructionProjection imagesTumor activityPhotonsNoise realizationsGa-67 imagingTumor estimationQuantitative imagingHistopathological stagingLocal backgroundTumor avidityAverage precisionX-rayCollimatorIterative algorithm
2001
Comparative Assessment of Energy-Based Methods of Compensating for Scatter and Lead X-Rays in Ga-67 SPECT Imaging
Moore S, Fakhri G, Maksud P. Comparative Assessment of Energy-Based Methods of Compensating for Scatter and Lead X-Rays in Ga-67 SPECT Imaging. 2001, 4: 2197-2198. DOI: 10.1109/nssmic.2001.1009260.Peer-Reviewed Original ResearchLead X-raysGa-67Energy windowArtificial neural networkGa-67 SPECT imagingSPECT imagesHigh-energy contaminationGa-67 SPECTPoisson noise realizationsActivity estimation taskTumor activity concentrationAnthropomorphic phantomEvaluable tumorsGS methodTumorMean square errorData setsOrgan uptakeProjection imagesLymphoma studiesNeural networkPixel valuesX-raySpherical tumorNoise realizations