title: Low-dose CT statistical iterative reconstruction via modified MRF regularization.
abstract: It is desirable to reduce the excessive radiation exposure to patients in repeated medical CT applications. One of the most effective ways is to reduce the X-ray tube current (mAs) or tube voltage (kVp). However, it is difficult to achieve accurate reconstruction from the noisy measurements. Compared with the conventional filtered back-projection (FBP) algorithm leading to the excessive noise in the reconstructed images, the approaches using statistical iterative reconstruction (SIR) with low mAs show greater image quality. To eliminate the undesired artifacts and improve reconstruction quality, we proposed, in this work, an improved SIR algorithm for low-dose CT reconstruction, constrained by a modified Markov random field (MRF) regularization. Specifically, the edge-preserving total generalized variation (TGV), which is a generalization of total variation (TV) and can measure image characteristics up to a certain degree of differentiation, was introduced to modify the MRF regularization. In addition, a modified alternating iterative algorithm was utilized to optimize the cost function. Experimental results demonstrated that images reconstructed by the proposed method could not only generate high accuracy and resolution properties, but also ensure a higher peak signal-to-noise ratio (PSNR) in comparison with those using existing methods.
authors.affiliation: National Key Laboratory for Electronic Measurement Technology, School of Information and Communication Engineering, North University of China, Taiyuan 030051, China; Key Laboratory of Instrumentation Science & Dynamic Measurement, School of Information and Communication Engineering, North University of China, Taiyuan 030051, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Shangguan
authors.affiliation: National Key Laboratory for Electronic Measurement Technology, School of Information and Communication Engineering, North University of China, Taiyuan 030051, China; Key Laboratory of Instrumentation Science & Dynamic Measurement, School of Information and Communication Engineering, North University of China, Taiyuan 030051, China.
authors.forename: Quan
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: National Key Laboratory for Electronic Measurement Technology, School of Information and Communication Engineering, North University of China, Taiyuan 030051, China; Key Laboratory of Instrumentation Science & Dynamic Measurement, School of Information and Communication Engineering, North University of China, Taiyuan 030051, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.affiliation: National Key Laboratory for Electronic Measurement Technology, School of Information and Communication Engineering, North University of China, Taiyuan 030051, China; Key Laboratory of Instrumentation Science & Dynamic Measurement, School of Information and Communication Engineering, North University of China, Taiyuan 030051, China; School of Applied Science, Taiyuan University of Science and Technology, Taiyuan 030024, China.
authors.forename: Xueying
authors.initials: X
authors.lastname: Cui
authors.affiliation: National Key Laboratory for Electronic Measurement Technology, School of Information and Communication Engineering, North University of China, Taiyuan 030051, China; Key Laboratory of Instrumentation Science & Dynamic Measurement, School of Information and Communication Engineering, North University of China, Taiyuan 030051, China.
authors.forename: Yunjiao
authors.initials: Y
authors.lastname: Bai
authors.affiliation: National Key Laboratory for Electronic Measurement Technology, School of Information and Communication Engineering, North University of China, Taiyuan 030051, China; Key Laboratory of Instrumentation Science & Dynamic Measurement, School of Information and Communication Engineering, North University of China, Taiyuan 030051, China. Electronic address: gzgtg@163.com.
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Gui
mesh_terms: D000465:Algorithms; D006257:Head / Q000000981:diagnostic imaging; D006801:Humans; D008390:Markov Chains; D008490:Medical Informatics; D010388:Pelvis / Q000000981:diagnostic imaging; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D059629:Signal-To-Noise Ratio; D014057:Tomography, X-Ray Computed / Q000379:methods* / Q000706:statistics & numerical data
keywords: CT; Markov random field; Regularization; Statistical iterative reconstruction; Total generalized variation