title: Fast diffusion imaging with high angular resolution.
abstract: High angular resolution diffusion imaging (HARDI) is a well-established method to help reveal the architecture of nerve bundles, but long scan times and geometric distortions inherent to echo planar imaging (EPI) have limited its integration into clinical protocols.
  
  
  
  A fast imaging method is proposed here that combines accelerated multishot diffusion imaging (AMDI), multiplexed sensitivity encoding (MUSE), and crossing fiber angular resolution of intravoxel structure (CFARI) to reduce spatial distortions and reduce total scan time. A multishot EPI sequence was used to improve geometrical fidelity as compared to a single-shot EPI acquisition, and acceleration in both k-space and diffusion sampling enabled reductions in scan time. The method is regularized and self-navigated for motion correction. Seven volunteers were scanned in this study, including four with volumetric whole brain acquisitions.
  
  
  
  The average similarity of microstructural orientations between undersampled datasets and their fully sampled counterparts was above 85%, with scan times below 5 min for whole-brain acquisitions. Up to 2.7-fold scan time acceleration along with four-fold distortion reduction was achieved.
  
  
  
  The proposed imaging strategy can generate HARDI results with relatively good geometrical fidelity and low scan duration, which may help facilitate the transition of HARDI from a successful research tool to a practical clinical one. Magn Reson Med 77:696-706, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
authors.affiliation: Department of Computer Science and Information Engineering, National Cheng-Kung University, Tainan, Taiwan.|Institute of Medical Informatics, National Cheng-Kung University, Tainan, Taiwan.
authors.forename: Tzu-Cheng
authors.initials: TC
authors.lastname: Chao
authors.affiliation: Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Jr-Yuan George
authors.initials: JG
authors.lastname: Chiou
authors.affiliation: Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.|Department of Radiology, Sahlgrenska University Hospital, Gothenburg University, Gothenburg, Sweden.
authors.forename: Stephan E
authors.initials: SE
authors.lastname: Maier
authors.affiliation: Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Bruno
authors.initials: B
authors.lastname: Madore
mesh_terms: D000465:Algorithms; D001921:Brain / Q000000981:diagnostic imaging*; D044962:Data Compression / Q000379:methods; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male
keywords: accelerated imaging; compressed sensing; high angular resolution diffusion imaging; parallel imaging