PANCREATIC-CARCINOMA - MR ASSESSMENT OF TUMOR INVASION OF THE PERIPANCREATIC VESSELS

Objective: Our goal was to determine the value of MRI in the assessmen t of vascular invasion in the preoperative staging of pancreatic carci noma. Materials and Methods: In 53 consecutive patients with an establ ished diagnosis of pancreatic ductal adenocarcinoma, SE T1-weighted an d breath-hold gradient echo images at 0.5 T were obtained before and a fter bolus injection of Gd-DTPA. Major peripancreatic vessels were eva luated for the presence of (a) no tumor invasion, (b) contiguity with tumor, and (c) tumor encasement. All patients subsequently underwent s urgery. Results of unenhanced and contrast-enhanced MRI studies were c ompared with the histologic findings in the resected specimens in 34 c ases and with the surgical findings in 19 nonresected cases. Results: In six patients, pathologic examination showed the presence of tumor c onfined to the pancreas with no vascular invasion. With MRI, five of t hese cases were correctly evaluated; in the remaining case, tumor-vess el contiguity was erroneously diagnosed. In 21 patients, tumor contigu ity with adjacent vessels was found at pathologic examination. At MRI, 16 of these cases were correctly assessed, and 5 were understaged as tumors confined to the pancreas. Of the remaining 26 patients, 7 had v ascular encasement by tumor at pathologic examination of the resected specimen; the other 19 patients had unresectable tumors encasing the a djacent vessels at surgical evaluation. MRI detected vascular encaseme nt in 21 of these 26 cases; in the other 5, tumor contiguity was incor rectly diagnosed. The overall accuracy of MRI for determining vascular invasion was 79%. Conclusion: MRI is a helpful method for preoperativ e assessment of vascular involvement due to pancreatic carcinoma.