title: [MRI in the evaluation of peripancreatic vessel invasion and resectability of pancreatic carcinoma].
abstract: OBJECTIVE
  To investigate the role of MRI in evaluating the peripancreatic vessel invasion and resectability of pancreatic carcinoma based on the comparison of MRI image with surgical exploration, and try to establish the criteria for assessment of the sensitivity, specificity and accuracy of resectability.
  
  
  METHODS
  Forty-one pancreatic carcinoma patients confirmed by pathology received preoperative plain and contrast enhanced MRI scan, and 37 of them had additional coronal MRA scan. Peripancreatic vessel invasion was preoperatively assessed based on MRI features, and the vessel invasion degree from the uninvolved to the severely involved was divided into 6 grades represented by 1, 2a, 2b, 3a, 3b and 4, respectively. Compared with the findings during the surgery, the sensitivity and specificity of each vessel invasion grade were studied and the receiver operator characteristic curve (ROC) was drawn. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of resectability evaluation based on 2 and 2a degree were calculated respectively. The resectability of involved arteries and veins of grade 2 were also analyzed.
  
  
  RESULTS
  Of the 41 patients, 22 had resectable tumor, with 20 curative resection and 2 palliative. Compared with the findings during surgery, seven vessels including three arteries and four veins were not correctly interpreted by MRI. If grade 1,2a,2b,3a and 3b was used as the resectable standard,respectively, the sensitivity to predict the unresectbility was 78.3%, 84.8%, 67.4%, 56.5% and 47.8%, respectively. Receiver operator characteristic curve demonstrated that grade 2a was the optimal critical point. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of grade 2a in predicting the unresectbility were 84.8%, 98.5%, 92.9%, 96.6% and 95.9%.
  
  
  CONCLUSIONS
  Our data showed that grade 2a (tumor involvement < 2 cm long and < 1/2 circumference of the vessel) may be more sensitive and accurate in predicting the resectability, which may be considered as the line of demarcation between the respectable and unresectable cases in clinical practice.
authors.affiliation: Department of Diagnostic Radiology, Zhongshan Hospital, Fudan University, Shanghai 200032, China.
authors.forename: Dong-Qing
authors.initials: DQ
authors.lastname: Wang
authors.forename: Meng-Su
authors.initials: MS
authors.lastname: Zeng
authors.forename: Da-Yong
authors.initials: DY
authors.lastname: Jin
authors.forename: Wen-Hui
authors.initials: WH
authors.lastname: Lou
authors.forename: Yuan
authors.initials: Y
authors.lastname: Ji
authors.forename: Sheng-Xiang
authors.initials: SX
authors.lastname: Rao
authors.forename: Xun
authors.initials: X
authors.lastname: Shi
authors.forename: Cai-Zhong
authors.initials: CZ
authors.lastname: Chen
authors.forename: Ren-Chen
authors.initials: RC
authors.lastname: Li
mesh_terms: D000328:Adult; D000368:Aged; D021441:Carcinoma, Pancreatic Ductal / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D002445:Celiac Artery / Q000473:pathology; D049448:Cholangiopancreatography, Magnetic Resonance; D005260:Female; D006499:Hepatic Artery / Q000473:pathology; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D017538:Mesenteric Artery, Superior / Q000473:pathology; D008642:Mesenteric Veins / Q000473:pathology; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D010179:Pancreas / Q000098:blood supply*; D010180:Pancreatectomy / Q000379:methods*; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D011169:Portal Vein / Q000473:pathology; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity