Image Reconstruction Method for Dual-energy Computed Tomography

Wenxiang Cong, Daniel Harrison, Yan Xi, Ge Wang


Published in:Fully3D 2017 Proceedings


dual-energy CT, polychromatic physical model, monochromatic image reconstruction, material decomposition.
Dual-energy computed tomography (CT) is to reconstruct images of an object from two projection datasets generated from two distinct x-ray source energy spectra. It can provide more accurate attenuation quantification than conventional CT with a single x-ray energy spectrum. In the diagnostic energy range, x-ray energy-dependent attenuation can be approximated as a linear combination of photoelectric absorption and Compton scattering. Hence, two physical components of x-ray attenuation can be determined from two spectrally informative projection datasets to achieve monochromatic imaging and material decomposition. In this paper, a projection-domain image reconstruction method is proposed to accurately quantify the two attenuation components for dual-energy CT. This method combines both an analytical algorithm and a single-variable optimization method to solve the non-linear polychromatic x-ray integral model, allowing an efficient and accurate decomposition of physical basis components. Numerical tests are performed to illustrate the merit of the proposed method. 
Wenxiang Cong
The Biomedical Imaging Center, Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180 USA
Daniel Harrison
The Biomedical Imaging Center, Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180 USA
Yan Xi
First Imaging Technology, Shanghai 201318, China
Ge Wang
The Biomedical Imaging Center, Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, NY 12180 USA
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