title: Diagnostic value of diffusion-weighted magnetic resonance imaging compared with fluorodeoxyglucose positron emission tomography/computed tomography for pancreatic malignancy: a meta-analysis using a hierarchical regression model.
abstract: OBJECTIVE
  To obtain diagnostic performance of diffusion-weighted magnetic resonance imaging (DWI) and fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in the detection of pancreatic malignancy.
  
  
  METHODS
  We performed a meta-analysis of all available studies of the diagnostic performance of DWI and PET/CT for pancreatic malignancy. MEDLINE, EMBASE, Cochrane library and some other databases were searched for initial studies. We determined sensitivities and specificities across studies, calculated positive and negative likelihood ratios (LR+ and LR-), and constructed summary receiver operating characteristic curves (SROC) using hierarchical regression models.
  
  
  RESULTS
  Across 16 studies with 804 patients, PET/CT sensitivity was 0.87 (95% confidence interval [CI], 0.82, 0.81) and specificity was 0.83 (95% CI, 0.71, 0.91). Overall, LR+ was 5.84 (95% CI, 4.59, 7.42) and LR- was 0.24 (95% CI, 0.17, 0.33). DWI sensitivity was 0.85 (95% CI, 0.74, 0.92) and specificity was 0.91 (95% CI, 0.71, 0.98). LR+ was 9.53 (95% CI, 2.41, 37.65) and LR- was 0.17 (95% CI, 0.09, 0.32). In subgroup analysis, the sensitivity of enhanced versus unenhanced PET/CT in the detection of pancreatic cancer was 0.91 (95% CI, 0.86, 0.96) versus 0.84 (95% CI, 0.78, 0.90) (P > 0.05), the specificity 0.88 (95% CI, 0.73, 1.00) versus 0.81 (95% CI, 0.69, 0.94) (P > 0.05).
  
  
  CONCLUSIONS
  Positron emission tomography/computed tomography (PET/CT) was highly sensitive and DWI was a highly specific modality in diagnosing patients with pancreatic malignancy. PET/CT and DWI could play different roles in diagnosing pancreatic carcinoma. Enhanced PET/CT seems to be superior to unenhanced PET/CT. Further larger prospective studies are needed to establish its value for diagnosis in pancreatic cancer.
authors.affiliation: Department of Radiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Lian-Ming
authors.initials: LM
authors.lastname: Wu
authors.forename: Jia-Ni
authors.initials: JN
authors.lastname: Hu
authors.forename: Jia
authors.initials: J
authors.lastname: Hua
authors.forename: Man-Ju
authors.initials: MJ
authors.lastname: Liu
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
authors.forename: Jian-Rong
authors.initials: JR
authors.lastname: Xu
mesh_terms: D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D019788:Fluorodeoxyglucose F18; D006801:Humans; D064847:Multimodal Imaging / Q000379:methods; D010190:Pancreatic Neoplasms / Q000175:diagnosis*; D049268:Positron-Emission Tomography; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
chemical_list: D019788:Fluorodeoxyglucose F18