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Computational and Mathematical Methods in Medicine
Volume 2013, Article ID 437917, 7 pages
http://dx.doi.org/10.1155/2013/437917
Research Article

Prior Image Guided Undersampled Dual Energy Reconstruction with Piecewise Polynomial Function Constraint

Dufan Wu,1,2 Li Zhang,1,2 Liang Li,1,2 Le Shen,1,2 and Yuxiang Xing1,2

1Key Laboratory of Particle & Radiation Imaging, Tsinghua University, Ministry of Education, Beijing 100084, China
2Department of Engineering Physics, Tsinghua University, Beijing 100084, China

Received 30 June 2013; Accepted 11 September 2013

Academic Editor: Tianye Niu

Copyright © 2013 Dufan Wu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Dual energy CT has the ability to give more information about the test object by reconstructing the attenuation factors under different energies. These images under different energies share identical structures but different attenuation factors. By referring to the fully sampled low-energy image, we show that it is possible to greatly reduce the sampling rate of the high-energy image in order to lower dose. To compensate the attenuation factor difference between the two modalities, we use piecewise polynomial fitting to fit the low-energy image to the high-energy image. During the reconstruction, the result is constrained by its distance to the fitted image, and the structural information thus can be preserved. An ASD-POCS-based optimization schedule is proposed to solve the problem, and numerical simulations are taken to verify the algorithm.