title: Added value of gadoxetic acid-enhanced hepatobiliary phase MR imaging in the diagnosis of hepatocellular carcinoma.
abstract: OBJECTIVE
  To determine the added value of hepatobiliary phase images in gadoxetic acid-enhanced magnetic resonance (MR) imaging in the evaluation of hepatocellular carcinoma (HCC).
  
  
  METHODS
  Institutional review board approved this retrospective study and waived the informed consent. Fifty-nine patients with 84 HCCs underwent gadoxetic acid-enhanced MR examinations that included 20-minute delayed hepatobiliary phase imaging. MR imaging was performed with a 1.5-T system in 19 patients and a 3.0-T system in 40 patients. A total of 113 hepatic nodules were documented for analysis. Three radiologists independently reviewed two sets of MR images: set 1, unenhanced (T1- and T2-weighted) and gadoxetic acid-enhanced dynamic images; set 2, hepatobiliary phase images and unenhanced and gadoxetic acid-enhanced dynamic images. For each observer, the diagnostic accuracy was compared by using the area under the alternative free-response receiver operating characteristic curve (A(z)). Sensitivity and specificity were also calculated and compared between the two sets.
  
  
  RESULTS
  For all observers, A(z) values were higher with the addition of the hepatobiliary phase. The observer who had the least experience in abdominal imaging (2 years) demonstrated significant improvement in A(z), from 0.895 in set 1 to 0.951 in set 2 (P = .049). Sensitivity increased with the addition of hepatobiliary phase images but did not reach statistical significance. Nine HCCs (10.7%) in six patients (10.1%) were seen only on hepatobiliary phase images.
  
  
  CONCLUSIONS
  Hepatobiliary phase images obtained after gadoxetic acid-enhanced dynamic MR imaging may improve diagnosis of HCC and assist in surgical planning.
authors.affiliation: Department of Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Shinchon-dong 134, Seodaemun-gu, Seoul 120-752, Korea.
authors.forename: Sung Soo
authors.initials: SS
authors.lastname: Ahn
authors.forename: Myeong-Jin
authors.initials: MJ
authors.lastname: Kim
authors.forename: Joon Seok
authors.initials: JS
authors.lastname: Lim
authors.forename: Hye-Suk
authors.initials: HS
authors.lastname: Hong
authors.forename: Yong Eun
authors.initials: YE
authors.lastname: Chung
authors.forename: Jin-Young
authors.initials: JY
authors.lastname: Choi
mesh_terms: D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis*; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008113:Liver Neoplasms / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA