title: Value of diffusion-weighted MRI for differentiating malignant from benign intraductal papillary mucinous neoplasms of the pancreas.
abstract: OBJECTIVE
  The purpose of this study was to evaluate whether the use of diffusion-weighted MRI (DWI) increases diagnostic accuracy in the differentiation of malignant from benign intraductal papillary mucinous neoplasms (IPMNs) of the pancreas over the accuracy of contrast-enhanced MRI with MRCP.
  
  
  METHODS
  A total of 61 patients with surgically resected IPMNs (19 malignant, 42 benign) who underwent gadoxetic acid-enhanced MRI, DWI, and MRCP were included. Two blinded observers evaluated two image sets, that is, conventional MRI with MRCP images versus combined conventional MRI with MRCP and DW images, and scored their confidence for malignancy of IPMNs. Qualitative analyses of the IPMNs were also conducted. Diagnostic performance (ROC curve analysis), accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were evaluated. The Fisher exact test was used to compare groups.
  
  
  RESULTS
  The diagnostic performance (area under the ROC curve [Az]) with respect to predicting malignancy of IPMNs improved significantly for both observers after additional review of DW images (p < 0.05). The diagnostic accuracy, sensitivity, specificity, PPV, and NPV of combined conventional and DW images were higher than those of conventional MR images alone. Diffusion restriction was more often present in malignant IPMNs (78.9%) than in benign IPMNs (16.7%) (p < 0.001) with excellent interobserver agreement (ĸ = 0.965).
  
  
  CONCLUSIONS
  Compared with conventional MRI alone, adding DWI to conventional MRI improves diagnostic accuracy with increased specificity for differentiating malignant from benign IPMNs of the pancreas.
authors.affiliation: 1 Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-dong, Gangnam-gu, Seoul 135-710, Korea.
authors.forename: Kyung Mi
authors.initials: KM
authors.lastname: Jang
authors.forename: Seong Hyun
authors.initials: SH
authors.lastname: Kim
authors.forename: Ji Hye
authors.initials: JH
authors.lastname: Min
authors.forename: Soon Jin
authors.initials: SJ
authors.lastname: Lee
authors.forename: Tae Wook
authors.initials: TW
authors.lastname: Kang
authors.forename: Sanghyeok
authors.initials: S
authors.lastname: Lim
authors.forename: Dongil
authors.initials: D
authors.lastname: Choi
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D021441:Carcinoma, Pancreatic Ductal / Q000473:pathology*; D003287:Contrast Media; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008297:Male; D015588:Observer Variation; D010190:Pancreatic Neoplasms / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA
keywords: MRI; diffusion-weighted imaging; intraductal papillary mucinous neoplasm; pancreas