title: Super-Resolution Reconstruction of Diffusion-Weighted Images using 4D Low-Rank and Total Variation
abstract: Diffusion-weighted imaging (DWI) provides invaluable information in white matter microstructure and is widely applied in neurological applications. However, DWI is largely limited by its relatively low spatial resolution. In this paper, we propose an image post-processing method, referred to as super-resolution reconstruction, to estimate a high spatial resolution DWI from the input low-resolution DWI, e.g., at a factor of 2. Instead of requiring specially designed DWI acquisition of multiple shifted or orthogonal scans, our method needs only a single DWI scan. To do that, we propose to model both the blurring and downsampling effects in the image degradation process where the low-resolution image is observed from the latent high-resolution image, and recover the latent high-resolution image with the help of two regularizations. The first regularization is 4-dimensional (4D) low-rank, proposed to gather self-similarity information from both the spatial domain and the diffusion domain of 4D DWI. The second regularization is total variation, proposed to depress noise and preserve local structures such as edges in the image recovery process. Extensive experiments were performed on 20 subjects, and results show that the proposed method is able to recover the fine details of white matter structures, and outperform other approaches such as interpolation methods, non-local means based upsampling, and total variation based upsampling.
authors.affiliation: Department of Radiology and BRIC, University of North Carolina at Chapel Hill, NC, USA
authors.forename: Feng
authors.initials: F
authors.lastname: Shi
authors.affiliation: Department of Radiology and BRIC, University of North Carolina at Chapel Hill, NC, USA|Section on Tissue Biophysics and Biomimetics, PPITS, National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
authors.forename: Jian
authors.initials: J
authors.lastname: Cheng
authors.affiliation: Department of Radiology and BRIC, University of North Carolina at Chapel Hill, NC, USA
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Radiology and BRIC, University of North Carolina at Chapel Hill, NC, USA
authors.forename: Pew-Thian
authors.initials: PT
authors.lastname: Yap
authors.affiliation: Department of Radiology and BRIC, University of North Carolina at Chapel Hill, NC, USA
authors.forename: Dinggang
authors.initials: D
authors.lastname: Shen