title: T2shuffling: Sharp, multicontrast, volumetric fast spin-echo imaging.
abstract: A new acquisition and reconstruction method called T2Shuffling is presented for volumetric fast spin-echo (three-dimensional [3D] FSE) imaging. T2Shuffling reduces blurring and recovers many images at multiple T2contrasts from a single acquisition at clinically feasible scan times (6-7 min).
  
  
  
  The parallel imaging forward model is modified to account for temporal signal relaxation during the echo train. Scan efficiency is improved by acquiring data during the transient signal decay and by increasing echo train lengths without loss in signal-to-noise ratio (SNR). By (1) randomly shuffling the phase encode view ordering, (2) constraining the temporal signal evolution to a low-dimensional subspace, and (3) promoting spatio-temporal correlations through locally low rank regularization, a time series of virtual echo time images is recovered from a single scan. A convex formulation is presented that is robust to partial voluming and radiofrequency field inhomogeneity.
  
  
  
  Retrospective undersampling and in vivo scans confirm the increase in sharpness afforded by T2Shuffling. Multiple image contrasts are recovered and used to highlight pathology in pediatric patients. A proof-of-principle method is integrated into a clinical musculoskeletal imaging workflow.
  
  
  
  The proposed T2Shuffling method improves the diagnostic utility of 3D FSE by reducing blurring and producing multiple image contrasts from a single scan. Magn Reson Med 77:180-195, 2017. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California, USA.
authors.forename: Jonathan I
authors.initials: JI
authors.lastname: Tamir
authors.affiliation: Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California, USA.
authors.forename: Martin
authors.initials: M
authors.lastname: Uecker
authors.affiliation: Global Applied Science Laboratory, GE Healthcare, Menlo Park, California, USA.
authors.forename: Weitian
authors.initials: W
authors.lastname: Chen
authors.affiliation: Global Applied Science Laboratory, GE Healthcare, Menlo Park, California, USA.
authors.forename: Peng
authors.initials: P
authors.lastname: Lai
authors.affiliation: Department of Radiology, Stanford University, Stanford, California, USA.
authors.forename: Marcus T
authors.initials: MT
authors.lastname: Alley
authors.affiliation: Department of Radiology, Stanford University, Stanford, California, USA.
authors.forename: Shreyas S
authors.initials: SS
authors.lastname: Vasanawala
authors.affiliation: Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Lustig
mesh_terms: D000328:Adult; D002648:Child; D005528:Foot / Q000000981:diagnostic imaging; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D059629:Signal-To-Noise Ratio
keywords: T2 imaging; compressed sensing; fast spin-echo; multicontrast