2016
Numerical observer for atherosclerotic plaque classification in spectral computed tomography
Lorsakul A, Fakhri G, Worstell W, Ouyang J, Rakvongthai Y, Laine A, Li Q. Numerical observer for atherosclerotic plaque classification in spectral computed tomography. Journal Of Medical Imaging 2016, 3: 035501-035501. PMID: 27429999, PMCID: PMC4940624, DOI: 10.1117/1.jmi.3.3.035501.Peer-Reviewed Original ResearchSignal-to-noise ratioChannelized Hotelling observerMatched filterSignal-to-noise ratio improvementDual-energy CTMultienergy CTSpectral computed tomographyBinary classification taskHotelling observerNumerical observationsArea under the receiver operating characteristic curveObjective image assessmentAcquisition methodImage atherosclerotic plaquesMaterial characterizationComputed tomographyClassification taskPerformance metricsAnthropomorphic digital phantomIdentification applicationsSpectral CT dataConventional CT systemsCalcified plaqueSignal variationsAnalytical computation
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