title: Detection of hepatic hypovascular metastases: 3D gradient echo MRI using a hepatobiliary contrast agent.
abstract: OBJECTIVE
  To assess the diagnostic performance of gadobenate dimeglumine-enhanced 3D gradient echo (3D-GRE) magnetic resonance imaging (MRI) for the detection of hepatic hypovascular metastases.
  
  
  METHODS
  We retrospectively analyzed the initial radiologic reports of MRI of 41 patients with suspected hepatic metastases. Seventy-nine metastatic lesions were confirmed by histopathology or intraoperative ultrasound (IOUS). The sensitivity and positive predictive values for the diagnosis of hepatic metastasis were determined among each MRI set (hepatobiliary phase, precontrast images, dynamic imaging). The diagnostic performance of dynamic image set and combined dynamic and hepatobiliary image set was also evaluated by two radiologists using alternative free response receiver operating characteristic (ROC) analysis.
  
  
  RESULTS
  The overall detection rate and positive predictive value of MR were 96.2% (76/79) and 96.2% (76/79), respectively. Images obtained with hepatobiliary phase 3D-GRE showed a significantly better detection rate compared to those with precontrast sequences or dynamic imaging (P = 0.008 and 0.016, respectively). Regarding lesions 1 cm or smaller, the detection rate was 90.3% (28/31). Each reader showed a higher Az value of the combined hepatobiliary image set than those of the dynamic image set.
  
  
  CONCLUSIONS
  3D-GRE MRI using a hepatobiliary contrast agent is an accurate tool in the detection of hepatic hypovascular metastases and improves detection rate compared with precontrast and dynamic imaging.
authors.affiliation: Department of Radiology, Research Institute of Radiological Science, Yonsei University Health System, Seoul, Republic of Korea.
authors.forename: Jin-Young
authors.initials: JY
authors.lastname: Choi
authors.forename: Jin-Sub
authors.initials: JS
authors.lastname: Choi
authors.forename: Myeong-Jin
authors.initials: MJ
authors.lastname: Kim
authors.forename: Joon Seok
authors.initials: JS
authors.lastname: Lim
authors.forename: Mi Suk
authors.initials: MS
authors.lastname: Park
authors.forename: Joo Hee
authors.initials: JH
authors.lastname: Kim
authors.forename: Yong Eun
authors.initials: YE
authors.lastname: Chung
mesh_terms: D000368:Aged; D000465:Algorithms; D001659:Biliary Tract / Q000473:pathology; D003287:Contrast Media; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008099:Liver / Q000473:pathology; D008113:Liver Neoplasms / Q000150:complications / Q000473:pathology* / Q000556:secondary*; D008297:Male; D008536:Meglumine / Q000031:analogs & derivatives*; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000150:complications / Q000473:pathology*; D009942:Organometallic Compounds; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C064572:gadobenic acid; D008536:Meglumine