title: Comparative MR study of hepatic fat quantification using single-voxel proton spectroscopy, two-point dixon and three-point IDEAL.
abstract: Hepatic fat fraction (HFF) was measured in 28 lean/obese humans by single-voxel proton spectroscopy (MRS), a two-point Dixon (2PD), and a three-point iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) method (3PI). For the lean, obese, and total subject groups, the range of HFF measured by MRS was 0.3-3.5% (1.1 +/- 1.4%), 0.3-41.5% (11.7 +/- 12.1), and 0.3-41.5% (10.1 +/- 11.6%), respectively. For the same groups, the HFF measured by 2PD was -6.3-2.2% (-2.0 +/- 3.7%), -2.4-42.9% (12.9 +/- 13.8%), and -6.3-42.9% (10.5 +/- 13.7%), respectively, and for 3PI they were 7.9-12.8% (10.1 +/- 2.0%), 11.1-49.3% (22.0 +/- 12.2%), and 7.9-49.3% (20.0 +/- 11.8%), respectively. The HFF measured by MRS was highly correlated with those measured by 2PD (r = 0.954, P < 0.001) and 3PI (r = 0.973, P < 0.001). With the MRS data as a reference, the percentages of correct differentiation between normal and fatty liver with the MRI methods ranged from 68-93% for 2PD and 64-89% for 3PI. Our study demonstrates that the apparent HFF measured by the MRI methods can significantly vary depending on the choice of water-fat separation methods and sequences. Such variability may limit the clinical application of the MRI methods, particularly when a diagnosis of early fatty liver needs to be performed. Therefore, protocol-specific establishment of cutoffs for liver fat content may be necessary.
authors.affiliation: Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut 06520-8043, USA. hyeonjin.kim@yale.edu
authors.forename: Hyeonjin
authors.initials: H
authors.lastname: Kim
authors.forename: Sara E
authors.initials: SE
authors.lastname: Taksali
authors.forename: Sylvie
authors.initials: S
authors.lastname: Dufour
authors.forename: Douglas
authors.initials: D
authors.lastname: Befroy
authors.forename: T Robin
authors.initials: TR
authors.lastname: Goodman
authors.forename: Kitt Falk
authors.initials: KF
authors.lastname: Petersen
authors.forename: Gerald I
authors.initials: GI
authors.lastname: Shulman
authors.forename: Sonia
authors.initials: S
authors.lastname: Caprio
authors.forename: R Todd
authors.initials: RT
authors.lastname: Constable
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D005234:Fatty Liver / Q000473:pathology*; D005260:Female; D006801:Humans; D016018:Least-Squares Analysis; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male