title: Simple Method for evaluating the degree of liver parenchymal enhancement in the hepatobiliary phase of gadoxetic acid-enhanced magnetic resonance imaging.
abstract: OBJECTIVE
  To establish a simple method to evaluate the degree of liver parenchymal enhancement in the hepatobiliary phase (HP) of gadoxetic acid-enhanced magnetic resonance imaging (MRI).
  
  
  METHODS
  Subjects comprised 75 patients with or without chronic liver disease who underwent gadoxetic acid-enhanced MRI and indocyanine green retention at 15 minutes (ICG-R15). HP images were used for data analysis. In the quantitative evaluation, liver-to-phantom signal intensity (SI) ratio (LPR), liver-to-portal vein SI ratio (LPVR), and liver-to-kidney SI ratio (LKR) were calculated. In qualitative visual assessment, liver-to-portal vein contrast (LPVC) and liver-to-kidney contrast (LKC) were assessed using a 5-point scale (1, hyperintense; 2, slightly hyperintense; 3, isointense; 4, slightly hypointense; 5, hypointense). Statistical evaluations included the Spearman's rank correlation test.
  
  
  RESULTS
  LPVC and LKC correlated significantly with LPR (ρ = -0.445, P < 0.001; ρ = -0.576, P < 0.001, respectively). LPVC and LKC showed significant correlations with LPVR and LKR (ρ = -0.659, P < 0.001; ρ = -0.674, P < 0.001, respectively). In addition, LPVC and LKC correlated significantly with ICG-R15 (ρ = 0.696, P < 0.001; ρ = 0.795, P < 0.001, respectively).
  
  
  CONCLUSIONS
  LPVC and LKC can be used as simple visual indicators to objectively assess the degree of liver parenchymal enhancement on HP of gadoxetic acid-enhanced MRI.
authors.affiliation: Department of Radiology, Kawasaki Medical School, Kurashiki, Japan. ttamada@med.kawasaki-m.ac.jp
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Tamada
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Ito
authors.forename: Akira
authors.initials: A
authors.lastname: Yamamoto
authors.forename: Kazuya
authors.initials: K
authors.lastname: Yasokawa
authors.forename: Atsushi
authors.initials: A
authors.lastname: Higaki
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kanki
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Sato
authors.forename: Daigo
authors.initials: D
authors.lastname: Taniomoto
authors.forename: Hiroki
authors.initials: H
authors.lastname: Higashi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D003287:Contrast Media; D058625:End Stage Liver Disease / 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; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA