title: 3D Multiecho Dixon for the Evaluation of Hepatic Iron and Fat in a Clinical Setting.
abstract: To prospectively evaluate a new 3D-multiecho-Dixon (3D-ME-Dixon) sequence for the quantification of hepatic iron and fat in a clinical setting.
  
  
  
  In all, 120 patients underwent 1.5T magnetic resonance imaging of the liver between December 2013 and June 2015 including the following three sequences: 3D-ME-Dixon with inline calculation of R2* and proton-density fat-fraction (PDFF) maps, single-voxel-spectroscopy (SVS), 2D multigradient-echo sequence (2D-ME-GRE). SVS and 2D-ME-GRE were used as reference for PDFF and R2*, respectively. R2*- and PDFF-values from 3D-ME-Dixon were compared with those of the reference. Linear regression analysis, Bland-Altman plots, and agreement parameters were calculated.
  
  
  
  In total, 103 patients were finally included (87 men and 16 women; mean age, 50.51 years); 17/120 were excluded due to fat/water-swaps or R2*-values exceeding the constraint of 400 1/s for 3D-ME-Dixon. A strong correlation (r = 0.992, P < 0.001) between R2* of 3D-ME-Dixon and the reference 2D-ME-GRE was found. Bland-Altman analysis revealed systematically lower values for 3D-ME-Dixon (16.499%). Using an adapted threshold of 57 1/s, 3D-ME-Dixon obtained a positive/negative percentage agreement (PPA/NPA) of 84.4%/91.4% for detecting hepatic iron overload. For hepatic fat the correlation between 3D-ME-Dixon and the reference SVS was strong (r = 0.957, P < 0.001); PPA/NPA was 88.3%/91.4%.
  
  
  
  The 3D-ME-Dixon sequence is a valuable tool for the evaluation of hepatic iron and fat in a clinical setting. Fat/water-swaps remain a drawback requiring improvements to the implementation and making it necessary to have proven conventional sequences at hand in case of an eventual occurrence.
  
  
  
  1. Technical Efficacy: Stage 2 J. MAGN. RESON. IMAGING 2017;46:793-800.
authors.affiliation: Department of Radiology, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Henninger
authors.affiliation: Department of Internal Medicine, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Heinz
authors.initials: H
authors.lastname: Zoller
authors.affiliation: MR Applications Development, Siemens, Healthcare Sector, Erlangen, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Kannengiesser
authors.affiliation: MR R&D Collaborations, Siemens Healthcare, Atlanta, Georgia, USA.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhong
authors.affiliation: Department of Radiology, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Werner
authors.initials: W
authors.lastname: Jaschke
authors.affiliation: Department of Radiology, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: Christian
authors.identifier: 0000-0002-6953-935X
authors.initials: C
authors.lastname: Kremser
mesh_terms: D000273:Adipose Tissue / Q000000981:diagnostic imaging*; D005234:Fatty Liver / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007501:Iron; D008099:Liver / Q000000981:diagnostic imaging* / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies
chemical_list: D007501:Iron
keywords: Dixon; MRI; fat; iron; liver; relaxometry