[MRI in the evaluation of peripancreatic vessel invasion and resectability of pancreatic carcinoma].
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.
Wang
Dong-Qing
DQ
Department of Diagnostic Radiology, Zhongshan Hospital, Fudan University, Shanghai 200032, China.
Zeng
Meng-Su
MS
Jin
Da-Yong
DY
Lou
Wen-Hui
WH
Ji
Yuan
Y
Rao
Sheng-Xiang
SX
Shi
Xun
X
Chen
Cai-Zhong
CZ
Li
Ren-Chen
RC
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