title: Multi-scale graph-cut algorithm for efficient water-fat separation.
abstract: To improve the accuracy and robustness to noise in water-fat separation by unifying the multiscale and graph cut based approaches to B0-correction.
  
  
  
  A previously proposed water-fat separation algorithm that corrects for B0field inhomogeneity in 3D by a single quadratic pseudo-Boolean optimization (QPBO) graph cut was incorporated into a multi-scale framework, where field map solutions are propagated from coarse to fine scales for voxels that are not resolved by the graph cut. The accuracy of the single-scale and multi-scale QPBO algorithms was evaluated against benchmark reference datasets. The robustness to noise was evaluated by adding noise to the input data prior to water-fat separation.
  
  
  
  Both algorithms achieved the highest accuracy when compared with seven previously published methods, while computation times were acceptable for implementation in clinical routine. The multi-scale algorithm was more robust to noise than the single-scale algorithm, while causing only a small increase (+10%) of the reconstruction time.
  
  
  
  The proposed 3D multi-scale QPBO algorithm offers accurate water-fat separation, robustness to noise, and fast reconstruction. The software implementation is freely available to the research community. Magn Reson Med 78:941-949, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
authors.affiliation: Department of Medical Radiation Physics, Karolinska University Hospital, Stockholm, Sweden.|Department of Clinical Science, Intervention and Technology, Karolinska Institute, Stockholm, Sweden.
authors.forename: Johan
authors.identifier: 0000-0002-0853-9305
authors.initials: J
authors.lastname: Berglund
authors.affiliation: Department of Radiology, Uppsala University Hospital, Uppsala, Sweden.|Department of Radiation Sciences, Umeå University, Umeå, Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Skorpil
mesh_terms: D000273:Adipose Tissue / Q000000981:diagnostic imaging*; D000465:Algorithms; D001834:Body Water / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007717:Knee / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging / Q000379:methods*; D059629:Signal-To-Noise Ratio
keywords: Dixon; chemical shift imaging; fat suppression; graph cuts; multi-scale processing; water-fat separation