title: Water-fat separation from a single spatiotemporally encoded echo based on nominal k-space peaking and joint regularized estimation.
abstract: OBJECTIVE
  To present a new high-resolution single-point water-fat separation algorithm based on the spatiotemporally encoded chemical shift imaging technique.
  
  
  BACKGROUND
  Identifying water and fat peaks on the ensemble of the nominal k-space profiles of all spatiotemporally encoded lines enables evaluation of the mean off-resonance frequencies of the two components. With utilization of the spatial smoothness and filtering regularizations, the water/fat profiles can be discriminated with twice joint linear least squares estimations line-by-line.
  
  
  METHODS
  The effectiveness of the proposed algorithm was assessed by experiments on oil-water phantoms and in vivo in rats at 7T using a spatiotemporally encoded variant of the multishot spin-echo sequence. The results were compared with those obtained from previously proposed 1-point Dixon, 2-point Dixon, and 3-point IDEAL methods.
  
  
  RESULTS
  The results demonstrate that the new technique can achieve high-quality water-fat separations, comparable in signal-to-noise ratio and contrast to the multipoint methods and is more robust in cases when large areas of low signals or motion artifacts jeopardize the results from the 1-point Dixon method.
  
  
  CONCLUSIONS
  The proposed technique is potentially a new viable alternative for single-point water-fat separation.
authors.affiliation: Department of Electronics Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory for Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
authors.forename: Congbo
authors.initials: C
authors.lastname: Cai
authors.forename: Jianhui
authors.initials: J
authors.lastname: Zhong
authors.forename: Zhong
authors.initials: Z
authors.lastname: Chen
mesh_terms: D000005:Abdomen / Q000033:anatomy & histology; D000273:Adipose Tissue / Q000033:anatomy & histology*; D000465:Algorithms; D000818:Animals; D001834:Body Water; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019047:Phantoms, Imaging; D051381:Rats; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D062211:Spatio-Temporal Analysis; D013382:Subtraction Technique
keywords: joint estimation; linear least squares estimation; single-point water-fat separation; smoothness regularization; spatiotemporal encoding