title: Penalized weighted least-squares approach for multienergy computed tomography image reconstruction via structure tensor total variation regularization.
abstract: Multienergy computed tomography (MECT) allows identifying and differentiating different materials through simultaneous capture of multiple sets of energy-selective data belonging to specific energy windows. However, because sufficient photon counts are not available in each energy window compared with that in the whole energy window, the MECT images reconstructed by the analytical approach often suffer from poor signal-to-noise and strong streak artifacts. To address the particular challenge, this work presents a penalized weighted least-squares (PWLS) scheme by incorporating the new concept of structure tensor total variation (STV) regularization, which is henceforth referred to as 'PWLS-STV' for simplicity. Specifically, the STV regularization is derived by penalizing higher-order derivatives of the desired MECT images. Thus it could provide more robust measures of image variation, which can eliminate the patchy artifacts often observed in total variation (TV) regularization. Subsequently, an alternating optimization algorithm was adopted to minimize the objective function. Extensive experiments with a digital XCAT phantom and meat specimen clearly demonstrate that the present PWLS-STV algorithm can achieve more gains than the existing TV-based algorithms and the conventional filtered backpeojection (FBP) algorithm in terms of both quantitative and visual quality evaluations.
authors.affiliation: Department of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong 510515, China; Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, Guangdong 510515, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Zeng
authors.affiliation: Department of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong 510515, China; Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, Guangdong 510515, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Department of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong 510515, China; Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, Guangdong 510515, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Huang
authors.affiliation: Department of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong 510515, China; Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, Guangdong 510515, China.
authors.forename: Zhaoying
authors.initials: Z
authors.lastname: Bian
authors.affiliation: Department of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong 510515, China; Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, Guangdong 510515, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong 510515, China; Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, Guangdong 510515, China.
authors.forename: Lijun
authors.initials: L
authors.lastname: Lu
authors.affiliation: Department of Biomedical Engineering, Southern Medical University, Guangzhou, Guangdong 510515, China; Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou, Guangdong 510515, China. Electronic address: jhma@smu.edu.cn.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Ma
mesh_terms: D000465:Algorithms; D007091:Image Processing, Computer-Assisted; D016018:Least-Squares Analysis; D014057:Tomography, X-Ray Computed
keywords: Multienergy computed tomography; Penalized weighted least-squares; Regularization; Structure tensor total variation