title: Comparison of computed tomography versus magnetic resonance imaging in assessing radiofrequency ablation margins after radiofrequency ablation in patients with hepatocellular carcinomas.
abstract: OBJECTIVE
  To assess the diagnostic value of magnetic resonance imaging (MRI) in the follow-up of patients with hepatocellular carcinomas treated with radiofrequency ablation (RFA) and to compare it with that of computed tomography (CT).
  
  
  METHODS
  From December 2009 to September 2011, 40 patients (47 hepatocellular carcinomas) were treated with RFA after transcatheter arterial chemoembolization and underwent MRI and CT for follow-up. RFA margins were assessed on a five-point scale with receiver operating characteristic curve analysis. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were evaluated.
  
  
  RESULTS
  The interobserver agreement rate for MRI was significantly higher (Kappa=0.935) than for CT (Kappa=0.714; P < 0.05). The scores of 1 and 5 points for MRI, which confirms the presence or absence of residual tumor, accounted for 89.4% (84/94), while for CT accounting for only 31.9% (30/94). The area under the receiver operating characteristic curve of MRI was significantly higher than that of CT (P < 0.05), as were the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of detection rate (mean, 100%, 96.4%, 76.9%, 100%, and 96.8% for MRI, respectively, vs. 30.0%, 57.1%, 10.3%, 87.7%, and 63.8% for CT).
  
  
  CONCLUSIONS
  MRI is superior to CT in assessing the RFA margins in terms of the diagnostic accuracy and detection rate .
authors.affiliation: Department of Radiology, Henan Cancer Hospital, Affiliated Cancer Hospital of Zhengzhou University, China.
authors.forename: Jin-rong
authors.initials: JR
authors.lastname: Qu
authors.forename: Cui-cui
authors.initials: CC
authors.lastname: Liu
authors.forename: Hong-kai
authors.initials: HK
authors.lastname: Zhang
authors.forename: Xiang
authors.initials: X
authors.lastname: Li
authors.forename: Jian-wei
authors.initials: JW
authors.lastname: Zhang
authors.forename: Jun-peng
authors.initials: JP
authors.lastname: Luo
authors.forename: Nan-nan
authors.initials: NN
authors.lastname: Shao
authors.forename: Shou-ning
authors.initials: SN
authors.lastname: Zhang
authors.forename: Yan-le
authors.initials: YL
authors.lastname: Li
authors.forename: Hai-Liang
authors.initials: HL
authors.lastname: Li
mesh_terms: D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D017115:Catheter Ablation; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018365:Neoplasm, Residual / Q000175:diagnosis; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed