title: Mapping of liver fat with triple-echo gradient echo imaging: validation against 3.0-T proton MR spectroscopy.
abstract: The purpose of this study was to validate a magnetic resonance imaging (MRI) technique for mapping liver fat, using (1)H magnetic resonance spectroscopy ((1)H-MRS) as the reference standard. In 91 patients with type 2 diabetes, 3.0-T single-voxel point-resolved (1)H-MRS was used to calculate the liver fat fraction (LFF) from the water (4.76 ppm) and methylene (1.33 ppm) peaks, corrected for T1 and T2 decays. LFF (corrected for T1 and T2* decays) was also obtained from the mean signal intensity on a map built from a triple-echo (consecutive in-phase, opposed-phase, and in-phase echo times) breath-hold gradient echo sequence, using basic image calculation functions (arithmetic mean, subtraction, division, multiplication by a numerical factor). Mean LFF was 8.9% (range, 0.9-33.5) by MRI and 8.8% (range, 0-34.1) by (1)H-MRS. Pearson's coefficient was 0.976 (P < 0.0001) and Lin's coefficient was 0.975 (P < 0.0001). Liver segment had no significant influence. With Bland-Altman analysis, 95.6% (87/91) of data points were within the limits of agreement. Given its excellent agreement with (1)H-MRS, our mapping technique can be used for visual and quantitative evaluation of liver fat in everyday practice.
authors.affiliation: Department of Radiology, Le Bocage University Hospital, Bd Maréchal de Lattre de Tassigny, 21000, Dijon, France. Boris.guiu@chu-dijon.fr
authors.forename: Boris
authors.initials: B
authors.lastname: Guiu
authors.forename: Romaric
authors.initials: R
authors.lastname: Loffroy
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Petit
authors.forename: Serge
authors.initials: S
authors.lastname: Aho
authors.forename: Douraied
authors.initials: D
authors.lastname: Ben Salem
authors.forename: David
authors.initials: D
authors.lastname: Masson
authors.forename: Patrick
authors.initials: P
authors.lastname: Hillon
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Cercueil
authors.forename: Denis
authors.initials: D
authors.lastname: Krause
mesh_terms: D000273:Adipose Tissue / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D017352:Echo-Planar Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008099:Liver / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D011522:Protons; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D011522:Protons