title: Multi-shot sensitivity-encoded diffusion data recovery using structured low-rank matrix completion (MUSSELS).
abstract: To introduce a novel method for the recovery of multi-shot diffusion weighted (MS-DW) images from echo-planar imaging (EPI) acquisitions.
  
  
  
  Current EPI-based MS-DW reconstruction methods rely on the explicit estimation of the motion-induced phase maps to recover artifact-free images. In the new formulation, the k-space data of the artifact-free DWI is recovered using a structured low-rank matrix completion scheme, which does not require explicit estimation of the phase maps. The structured matrix is obtained as the lifting of the multi-shot data. The smooth phase-modulations between shots manifest as null-space vectors of this matrix, which implies that the structured matrix is low-rank. The missing entries of the structured matrix are filled in using a nuclear-norm minimization algorithm subject to the data-consistency. The formulation enables the natural introduction of smoothness regularization, thus enabling implicit motion-compensated recovery of the MS-DW data.
  
  
  
  Our experiments on in-vivo data show effective removal of artifacts arising from inter-shot motion using the proposed method. The method is shown to achieve better reconstruction than the conventional phase-based methods.
  
  
  
  We demonstrate the utility of the proposed method to effectively recover artifact-free images from Cartesian fully/under-sampled and partial Fourier acquired data without the use of explicit phase estimates. Magn Reson Med 78:494-507, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
authors.affiliation: Department of Psychiatry, University of Iowa, Iowa City, Iowa, USA.
authors.forename: Merry
authors.initials: M
authors.lastname: Mani
authors.affiliation: Department of Electrical and Computer Engineering, University of Iowa, Iowa City, Iowa, USA.
authors.forename: Mathews
authors.initials: M
authors.lastname: Jacob
authors.affiliation: GE Healthcare.
authors.forename: Douglas
authors.initials: D
authors.lastname: Kelley
authors.affiliation: Department of Psychiatry, University of Iowa, Iowa City, Iowa, USA.|Department of Radiology, University of Iowa, Iowa City, Iowa, USA.|Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa, USA.
authors.forename: Vincent
authors.initials: V
authors.lastname: Magnotta
mesh_terms: D000328:Adult; D000465:Algorithms; D001921:Brain / Q000000981:diagnostic imaging*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D017352:Echo-Planar Imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D012815:Signal Processing, Computer-Assisted
keywords: annihilating filter; calibration-less; motion compensation; multi-shot diffusion; regularized recovery; structured low-rank