title: Focal fat deposition at liver MRI with gadobenate dimeglumine and gadoxetic acid: Quantitative and qualitative analysis.
abstract: OBJECTIVE
  To evaluate the image findings of focal fat deposition (FFD) in the liver on gadobenate dimeglumine (Gd-BOPTA)- and gadoxetic acid (Gd-EOB-DTPA)-enhanced MRI, particularly during the hepatobiliary phase (HBP), and the relationship between relative enhancement (RE) and fat signal fraction (FSF) of FFD.
  
  
  METHODS
  Twenty-one patients with 27 FFDs (mean diameter, 21.9mm), which showed low signal intensity on opposed-phase compared with in-phase MRI, were retrospectively evaluated. RE of the liver (REliver) and FFD (REFFD) and liver-to-lesion contrast-to-noise ratio (CNR) of FFD were measured on dynamic phases and HBP images with fat-saturated in-phase gradient-echo sequence. The FSF of each FFD was measured on in- and opposed-phase dual gradient-echo images. We qualitatively analyzed imaging findings of FFDs, including signal intensity, shape, margin, and homogeneity on HBP images, and enhancement pattern during dynamic phases. The correlations between REFFD and FSF and between CNR and FSF on HBP images were evaluated using Pearson's correlation tests and a simple linear regression model.
  
  
  RESULTS
  There were no significant differences between REFFD and REliver in dynamic phases and HBP, regardless of contrast agents (p≥0.075). On HBP images, CNR (p=0.008) but not REFFD (p=0.122) was significantly correlated with FSF of FFDs (mean FSF, 19%). On HBP images, 21 of the 27 (77.8%) FFDs were hypointense, and 17 (63%) were homogeneous. Of the 21 hypointense FFDs, 12 (57.1%) had an ovoid shape and 11 (52.4%) were well margined. Although the 27 FFDs showed various enhancement patterns, 17 (63%) showed no enhancement.
  
  
  CONCLUSIONS
  Most FFDs appeared as hypointense lesions on Gd-BOPTA- and Gd-EOB-DTPA-enhanced MRI during HBP, with various enhancement patterns during dynamic contrast-enhanced phases. REFFD on HBP images was not significantly correlated with FSF of low grade FFDs.
authors.affiliation: Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Asanbyeongwon-gil 86, Songpa-Gu, Seoul 138-736, Korea.
authors.forename: Suk Keu
authors.initials: SK
authors.lastname: Yeom
authors.forename: Jae Ho
authors.initials: JH
authors.lastname: Byun
authors.forename: Hye Jin
authors.initials: HJ
authors.lastname: Kim
authors.forename: Seong Ho
authors.initials: SH
authors.lastname: Park
authors.forename: Namkug
authors.initials: N
authors.lastname: Kim
authors.forename: Yong Moon
authors.initials: YM
authors.lastname: Shin
authors.forename: Pyo Nyun
authors.initials: PN
authors.lastname: Kim
mesh_terms: D000273:Adipose Tissue / Q000473:pathology*; D050154:Adiposity; D000328:Adult; D000368:Aged; D003287:Contrast Media; D005234:Fatty Liver / Q000473:pathology*; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008099:Liver / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008536:Meglumine / Q000031:analogs & derivatives*; D008875:Middle Aged; D015588:Observer Variation; D009942:Organometallic Compounds; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C073590:gadolinium ethoxybenzyl DTPA; C064572:gadobenic acid; D008536:Meglumine; D019786:Gadolinium DTPA