title: Compressed sensing of spatial electron paramagnetic resonance imaging.
abstract: OBJECTIVE
  To improve image quality and reduce data requirements for spatial electron paramagnetic resonance imaging (EPRI) by developing a novel reconstruction approach using compressed sensing (CS).
  
  
  METHODS
  EPRI is posed as an optimization problem, which is solved using regularized least-squares with sparsity promoting penalty terms, consisting of the l1 norms of the image itself and the total variation of the image. Pseudo-random sampling was employed to facilitate recovery of the sparse signal. The reconstruction was compared with the traditional filtered back-projection reconstruction for simulations, phantoms, isolated rat hearts, and mouse gastrointestinal (GI) tracts labeled with paramagnetic probes.
  
  
  RESULTS
  A combination of pseudo-random sampling and CS was able to generate high-fidelity EPR images at high acceleration rates. For three-dimensional (3D) phantom imaging, CS-based EPRI showed little visual degradation at nine-fold acceleration. In rat heart datasets, CS-based EPRI produced high quality images with eight-fold acceleration. A high resolution mouse GI tract reconstruction demonstrated a visual improvement in spatial resolution and a doubling in signal-to-noise ratio (SNR).
  
  
  CONCLUSIONS
  A novel 3D EPRI reconstruction using compressed sensing was developed and offers superior SNR and reduced artifacts from highly undersampled data.
authors.affiliation: Center for Biomedical EPR Spectroscopy and Imaging, Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.
authors.forename: David H
authors.initials: DH
authors.lastname: Johnson
authors.forename: Rizwan
authors.initials: R
authors.lastname: Ahmad
authors.forename: Guanglong
authors.initials: G
authors.lastname: He
authors.forename: Alexandre
authors.initials: A
authors.lastname: Samouilov
authors.forename: Jay L
authors.initials: JL
authors.lastname: Zweier
mesh_terms: D000465:Algorithms; D000818:Animals; D044962:Data Compression; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D006321:Heart / Q000033:anatomy & histology; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional; D007422:Intestines / Q000033:anatomy & histology; D051379:Mice; D019047:Phantoms, Imaging; D051381:Rats
keywords: compressed sensing; electron paramagnetic resonance imaging; filtered backprojection; image processing