Pancreatic adenocarcinoma: assessment of vascular invasion with high-field MR imaging and a phased-array coil.

Abstract

We performed this study to determine the value of MR imaging for assessing vascular invasion in preoperative staging of pancreatic carcinoma. In 73 consecutive patients with an established diagnosis of pancreatic duct adenocarcinoma, spin-echo T1-weighted and breath-hold multiplanar gradient-recalled (MPGR) images were obtained at 1.5 T with a phased-array coil before and after bolus injection of gadopentetate dimeglumine. Major peripancreatic vessels were evaluated for contiguity with tumor and tumor encasement. All patients subsequently underwent surgery. Results of unenhanced and enhanced MR imaging studies were compared with the histologic findings in the resected specimens of 49 tumors and with the surgical findings of 24 nonresected tumors. In 39 patients, tumor contiguity with adjacent vessels was found at pathologic examination. Of the remaining 34 patients, 10 had vascular encasement by tumor seen on pathologic examination of the resected specimen; the other 24 had unresectable tumors encasing adjacent vessels at surgical evaluation. In the assessment of vascular tumor contiguity, the accuracy was 85% for unenhanced spin-echo T1-weighted imaging, 87% for enhanced spin-echo T1-weighted imaging, 67% for unenhanced MPGR imaging, and 69% for enhanced MPGR imaging. In the assessment of vascular tumor encasement, the accuracy was 91% for unenhanced spin-echo T1-weighted imaging, 94% for enhanced spin-echo T1-weighted imaging, 74% for unenhanced MPGR imaging, and 76% for enhanced MPGR imaging. MR imaging is helpful for preoperative assessment of vascular involvement caused by pancreatic carcinoma. For this purpose, unenhanced and enhanced spin-echo T1-weighted images seem to be more accurate than images obtained with other pulse sequences.