title: Detection of liver metastases using gadoxetic-enhanced dynamic and 10- and 20-minute delayed phase MR imaging.
abstract: OBJECTIVE
  To assess the incremental value of hepatobiliary phase images in gadoxetate disodium-enhanced magnetic resonance imaging (MRI), and to compare diagnostic accuracy and lesion conspicuity on 10- and 20-minute delayed images for preoperative detection of hepatic metastases with subgroup analysis according to size and history of chemotherapy.
  
  
  METHODS
  Forty-six patients with 107 metastases who underwent surgery after gadoxetate disodium-enhanced MRI were evaluated. Four observers independently interpreted three sets: dynamic set comprising precontrast T1-, T2-weighted, and dynamic images; 10-minute set comprising dynamic set and 10-minute delayed; 20-minute set comprising 10-minute set and 20-minute delayed. Diagnostic accuracy was compared with subgroup analysis. Liver-to-lesion signal ratio (SR) was calculated using the region of interest method and compared.
  
  
  RESULTS
  Mean A(z) and sensitivities were significantly higher for 10- (A(z) = 0.894, sensitivity = 95.6%) and 20-minute (0.910, 97.2%) than dynamic set (0.813, 79.9%) (P < 0.001), with no significant difference between 10- and 20-minute sets (P = 0.140). In patients with small (≤1 cm) metastases and a history of chemotherapy, sensitivities were significantly higher with 10- (88.2%) and 20-minute (91.6%) sets than dynamic set (48.6%) (P < 0.001). SR was significantly higher for 10- and 20-minute delayed than precontrast and dynamic, with significantly higher SR on 20- than 10-minute delayed.
  
  
  CONCLUSIONS
  Regardless of size or prior chemotherapy, detection of hepatic metastases was significantly improved by adding hepatobiliary phase images without significant differences between 10- and 20-minute delayed.
authors.affiliation: Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Hyeon Tae
authors.initials: HT
authors.lastname: Jeong
authors.forename: Myeong-Jin
authors.initials: MJ
authors.lastname: Kim
authors.forename: Mi-Suk
authors.initials: MS
authors.lastname: Park
authors.forename: Jin-Young
authors.initials: JY
authors.lastname: Choi
authors.forename: Jin Sub
authors.initials: JS
authors.lastname: Choi
authors.forename: Kyung Sik
authors.initials: KS
authors.lastname: Kim
authors.forename: Gi Hong
authors.initials: GH
authors.lastname: Choi
authors.forename: Sang-Joon
authors.initials: SJ
authors.lastname: Shin
mesh_terms: D000704:Analysis of Variance; D003131:Combined Modality Therapy; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000188:drug therapy / Q000556:secondary* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA