title: Quantitative evaluation of liver function with use of gadoxetate disodium-enhanced MR imaging.
abstract: OBJECTIVE
  To determine whether liver function correlating with indocyanine green (ICG) clearance could be estimated quantitatively from gadoxetate disodium-enhanced magnetic resonance (MR) images.
  
  
  METHODS
  This retrospective study was approved by the institutional review board, and the requirement for informed consent was waived. Twenty-three consecutive patients who underwent an ICG clearance test and gadoxetate disodium-enhanced MR imaging with the same parameters as were used for a preoperative examination were chosen. The hepatocellular uptake index (HUI) from liver volume (V(L))and mean signal intensity of the liver on contrast-enhanced T1-weighted images with fat suppression (L(20)) and mean signal intensity of the spleen on contrast-enhanced T1-weighted images with fat suppression (S(20)) on 3D gradient-echo T1-weighted images with fat suppression obtained at 20 minutes after gadoxetate disodium (0.025 mmol per kilogram of body weight) administration was determined with the following equation: V(L)[(L(20)/S(20)) - 1]. The correlation of the plasma disappearance rate of ICG (ICG-PDR) and various factors derived from MR imaging, including HUI, iron and fat deposition in the liver and spleen, and spleen volume (V(S)), were evaluated with stepwise multiple regression analysis. The difference between the ratio of the remnant HUI to the HUI of the total liver (rHUI/HUI) and ratio of the liver remnant V(L) to the total V(L) (rV(L)/V(L)) was evaluated in four patients who had segmental heterogeneity of liver function.
  
  
  RESULTS
  HUI and V(S) were the factors significantly correlated with ICG-PDR (R = 0.87). The mean value and its 95% confidence interval were 0.18 and 0.01 to 0.34, respectively, for the following calculation: (rHUI/HUI) - (rV(L)/V(L)).
  
  
  CONCLUSIONS
  The liver function correlating with ICG-PDR can be estimated quantitatively from the signal intensities and the volumes of the liver and spleen on gadoxetate disodium-enhanced MR images, which may improve the estimation of segmental liver function.
authors.affiliation: Department of Radiology, University of Chicago, Chicago, Ill, USA. a_yamada@shinshu-u.ac.jp
authors.forename: Akira
authors.initials: A
authors.lastname: Yamada
authors.forename: Takeshi
authors.initials: T
authors.lastname: Hara
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.forename: Yasunari
authors.initials: Y
authors.lastname: Fujinaga
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Ueda
authors.forename: Masumi
authors.initials: M
authors.lastname: Kadoya
authors.forename: Kunio
authors.initials: K
authors.lastname: Doi
mesh_terms: D000369:Aged, 80 and over; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008099:Liver / Q000473:pathology / Q000503:physiopathology*; D008107:Liver Diseases / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology*; D008111:Liver Function Tests / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA