An Iterative Algorithm with Simultaneously Updating the Spectrum and the Image of Dual Energy Computed Tomography

Shaojie Chang, Xi Chen, Xuanqin Mou


Published in:Fully3D 2017 Proceedings


DECT, spectrum estimation, iterative recon-struction
Knowing the X-ray spectrum is important to dual energy computed tomography (DECT) reconstruction. Whereas the spectrum is not always available in practice. In addition, the reconstructed image of DECT is extremely sensitive to noise which demands special noise suppression strategy in recon-struction algorithm design. Hence the iterative reconstruction methods by inducing regularization to elevate the image quality attract more attention. In this paper, we develop an iterative algorithm with simultaneously updating the spectrum and the image of DECT, which did not need the knowledge of the spectrum in advance. Namely, spectrum estimation and iterative reconstruction are incorporated in an iterative framework. The estimated spectrum and the reconstructed images are obtained si-multaneously with the proposed algorithm. Two sets of simulation experiment with different phantoms were adopted for evaluation. In the experiment, the spectrum estimated by the image based reconstruction results are utilized as the initially estimated spectrum. In comparison with the initially estimated spectrum, experimental results validated that the proposed method can increase the accuracy of the estimated spectrum. Besides, the quality of the reconstructed density images has been improved by this work at the same time.
Shaojie Chang
Institute of Image processing and Pattern recognition, Xi'an Jiaotong University, Xi’an, Shaanxi 710049, China.
Xuanqin Mou
Institute of Image processing and Pattern recognition, Xi'an Jiaotong University, Xi’an, Shaanxi 710049, China.
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