title: Stability of liver proton density fat fraction and changes in R 2* measurements induced by administering gadoxetic acid at 3T MRI.
abstract: To assess changes in liver proton density fat fraction (PDFF) and R 2* measurements in the presence of changes in tissue relaxation rates induced by administrating gadoxetic acid, using two different image reconstruction methods at 3T MRI.
  
  
  
  Forty-five patients were imaged at 3T with chemical-shift-based MRI sequences before and 20 min after administration of gadoxetic acid. Image reconstructions were performed using hybrid and complex methods to obtain PDFF and R 2* images. A single radiologist measured PDFF and R 2* values on precontrast and postcontrast images. Precontrast and postcontrast PDFF values were compared using intraclass correlation coefficient (ICC), linear regression, and Bland-Altman analysis. Changes in R 2* values from precontrast to postcontrast were correlated with relative liver enhancement (RLE) based on signal intensities on T 1-weighted images using Spearman's rank correlation.
  
  
  
  PDFF values were similar between precontrast and postcontrast images (ICC = 0.99, linear regression slopes = 0.98, mean difference = -0.21 to -0.31%). PDFF measurements were stable between precontrast and postcontrast images. Changes in R 2* values were correlated with RLE (p < 0.001, r = 0.49-0.71).
  
  
  
  PDFF measurements from both image reconstruction methods are stable in the presence of changes in tissue relaxation rates after administering gadoxetic acid at 3T MRI. Changes in R 2* values correlate with established measures of gadoxetic acid uptake based on T 1-weighted images.
authors.affiliation: Department of Radiology, Duke University Medical Center, Box 3808, Durham, NC, 27710, USA.|Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Keitaro
authors.initials: K
authors.lastname: Sofue
authors.affiliation: Siemens Healthcare, Atlanta, GA, USA.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhong
authors.affiliation: Siemens Healthcare, Erlangen, Germany.
authors.forename: Marcel D
authors.initials: MD
authors.lastname: Nickel
authors.affiliation: Siemens Healthcare, Morrisville, NC, USA.
authors.forename: Brian M
authors.initials: BM
authors.lastname: Dale
authors.affiliation: Department of Radiology, Duke University Medical Center, Box 3808, Durham, NC, 27710, USA. mustafa.bashir@duke.edu.|Center for Advanced Magnetic Resonance Development, Duke University Medical Center, Durham, NC, USA. mustafa.bashir@duke.edu.
authors.forename: Mustafa R
authors.initials: MR
authors.lastname: Bashir
mesh_terms: D000273:Adipose Tissue / Q000000981:diagnostic imaging; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008099:Liver / Q000000981:diagnostic imaging*; D008107:Liver Diseases / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011522:Protons; D015203:Reproducibility of Results; D055815:Young Adult
chemical_list: D003287:Contrast Media; D011522:Protons; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA
keywords: 3T; Fat quantification; Gadoxetic acid; Hepatic steatosis; MRI; R 2*