title: Bias correction for magnetic resonance images via joint entropy regularization.
abstract: Due to the imperfections of the radio frequency (RF) coil or object-dependent electrodynamic interactions, magnetic resonance (MR) images often suffer from a smooth and biologically meaningless bias field, which causes severe troubles for subsequent processing and quantitative analysis. To effectively restore the original signal, this paper simultaneously exploits the spatial and gradient features of the corrupted MR images for bias correction via the joint entropy regularization. With both isotropic and anisotropic total variation (TV) considered, two nonparametric bias correction algorithms have been proposed, namely IsoTVBiasC and AniTVBiasC. These two methods have been applied to simulated images under various noise levels and bias field corruption and also tested on real MR data. The test results show that the proposed two methods can effectively remove the bias field and also present comparable performance compared to the state-of-the-art methods.
authors.affiliation: School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China School of Information Technologies, The University of Sydney, NSW 2006, Australia.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Wang
authors.forename: Yong
authors.initials: Y
authors.lastname: Xia
authors.forename: Pei
authors.initials: P
authors.lastname: Dong
authors.forename: Jianhua
authors.initials: J
authors.lastname: Luo
authors.forename: Qiu
authors.initials: Q
authors.lastname: Huang
authors.forename: Dagan
authors.initials: D
authors.lastname: Feng
authors.forename: Yuanxiang
authors.initials: Y
authors.lastname: Li
mesh_terms: D000465:Algorithms; D016880:Anisotropy; D000843:Ankle Joint / Q000473:pathology*; D001921:Brain / Q000473:pathology*; D003198:Computer Simulation; D016208:Databases, Factual; D019277:Entropy; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008962:Models, Theoretical; D015203:Reproducibility of Results
keywords: Bias correction; joint entropy; magnetic resonance (MR) images; total variation (TV)