title: Stationary wavelet transform for under-sampled MRI reconstruction.
abstract: In addition to coil sensitivity data (parallel imaging), sparsity constraints are often used as an additional lp-penalty for under-sampled MRI reconstruction (compressed sensing). Penalizing the traditional decimated wavelet transform (DWT) coefficients, however, results in visual pseudo-Gibbs artifacts, some of which are attributed to the lack of translation invariance of the wavelet basis. We show that these artifacts can be greatly reduced by penalizing the translation-invariant stationary wavelet transform (SWT) coefficients. This holds with various additional reconstruction constraints, including coil sensitivity profiles and total variation. Additionally, SWT reconstructions result in lower error values and faster convergence compared to DWT. These concepts are illustrated with extensive experiments on in vivo MRI data with particular emphasis on multiple-channel acquisitions.
authors.affiliation: Robarts Research Institute, Western University, Canada; Biomedical Engineering, Western University, Canada. Electronic address: mkayvan@gmail.com.
authors.forename: Mohammad H
authors.initials: MH
authors.lastname: Kayvanrad
authors.affiliation: Robarts Research Institute, Western University, Canada; Biomedical Engineering, Western University, Canada.
authors.forename: A Jonathan
authors.initials: AJ
authors.lastname: McLeod
authors.affiliation: Robarts Research Institute, Western University, Canada; Biomedical Engineering, Western University, Canada.
authors.forename: John S H
authors.initials: JS
authors.lastname: Baxter
authors.affiliation: Robarts Research Institute, Western University, Canada; Biomedical Engineering, Western University, Canada; Medical biophysics, Western University, Canada.
authors.forename: Charles A
authors.initials: CA
authors.lastname: McKenzie
authors.affiliation: Robarts Research Institute, Western University, Canada; Biomedical Engineering, Western University, Canada; Medical biophysics, Western University, Canada.
authors.forename: Terry M
authors.initials: TM
authors.lastname: Peters
mesh_terms: D000465:Algorithms; D016477:Artifacts; D001921:Brain / Q000473:pathology*; D044962:Data Compression / Q000379:methods; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D016012:Poisson Distribution; D015203:Reproducibility of Results; D059629:Signal-To-Noise Ratio; D058067:Wavelet Analysis
keywords: Accelerated MR imaging; Compressed sensing; MRI reconstruction; Parallel imaging; Sparse reconstruction; k-space under-sampling