title: Role of diffusion-weighted magnetic resonance imaging in differentiating malignancies from benign ovarian tumors.
abstract: OBJECTIVE
  We conducted a case-control study to evaluate the diagnostic values of computed tomography (CT) and diffusion-weighted magnetic resonance imaging (DW-MRI) in differentiating malignancies from benign ovarian tumors and a meta-analysis to further confirm our results on DW-MRI.
  
  
  METHODS
  Totally 64 patients pathologically confirmed as ovarian cancer were included in this study. CT scan and DWI-MRI were performed and analyzed to get compared with pathological results, thereby assessing their accuracy, sensitivity and specificity. Meta-analysis was conducted by database searching and strict eligibility criteria, using STATA 12.0 (Stata Corp, College Station, TX, USA) software.
  
  
  RESULTS
  The accuracy, sensitivity, specificity, positive predictive value and negative predictive value for diagnosis of ovarian cancer in CT were 81.82%, 84.48%, 76.67%, 87.50% and 71.88%, respectively; those in DW-MRI were 89.77%, 93.10%, 83.33%, 91.53% and 86.21%, respectively. The Kappa coefficient of DW-MRI (K = 0.771) compared with pathological results was higher than CT (K = 0.602). The average apparent diffusion coefficient values of DW-MRI in diagnosis of benign and malignant ovarian tumors suggested statistically significant difference (1.325 ± 0.269×10(-3) mm(2)/s vs. 0.878 ± 0.246×10(-3) mm(2)/s, P < 0.001). Meta-analysis results showed that the combined sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and diagnostic odds ratio of DW-MRI in discriminating benign versus malignant ovarian tumors were 0.93, 0.88, 7.70, 0.08 and 101.24, respectively. The area under the summary receiver operating characteristic curve was 0.95.
  
  
  CONCLUSIONS
  Both CT and DW-MRI were of great diagnostic value in differentiating malignancies from benign ovarian tumors, while DW-MRI was superior to CT with higher accuracy, sensitivity and specificity.
authors.affiliation: Department of Radiology, Yiwu Central HospitalYiwu 322000, P. R. China; Yiwu Hospital of Wenzhou Medical UniversityYiwu 322000, P. R. China.
authors.forename: Xinhua
authors.initials: X
authors.lastname: Fan
authors.affiliation: Department of Radiology, Yiwu Central HospitalYiwu 322000, P. R. China; Yiwu Hospital of Wenzhou Medical UniversityYiwu 322000, P. R. China.
authors.forename: Hongbin
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Yiwu Central HospitalYiwu 322000, P. R. China; Yiwu Hospital of Wenzhou Medical UniversityYiwu 322000, P. R. China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Meng
authors.affiliation: Department of Radiology, Yiwu Central HospitalYiwu 322000, P. R. China; Yiwu Hospital of Wenzhou Medical UniversityYiwu 322000, P. R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Yiwu Central HospitalYiwu 322000, P. R. China; Yiwu Hospital of Wenzhou Medical UniversityYiwu 322000, P. R. China.
authors.forename: Chuge
authors.initials: C
authors.lastname: Zhang
keywords: Ovarian cancer; apparent diffusion coefficient value; case-control; computed tomography; diffusion-weighted magnetic resonance imaging; meta-analysis