Evaluation of contrast enhancement patterns in pancreatic tumors by coded harmonic sonographic imaging with a microbubble contrast agent

Objective. The purpose of the study was to assess patterns of primary pancreatic lesions by contrast-enhanced sonography for differentiating ductal carcinomas from other pancreatic tumors. Methods. One hundred six consecutive patients with pancreatic masses, consisting of 83 ductal carcinomas, 7 endocrine carcinomas, 5 intraductal papillary mucinous tumors, 3 cases of autoimmune-related pancreatitis, 3 solid pseudopapillary tumors, 2 cases of chronic pancreatitis, I serous cystadenoma, 1 osteoclastoid giant cell tumor, and 1 follicular lymphoma, were examined by contrast-enhanced sonography with coded harmonic imaging in a phase inversion harmonic technique. The contrast enhancement patterns were assessed, and specimens removed during pancreatectomy were subjected to pathologic examination. Results. Internal tumoral vascularity was detected in 47 (56.6%) of the 83 ductal carcinomas. Vascular image spreading and homogeneous staining throughout the tumors were observed in all endocrine carcinomas. Two of the 5 intraductal papillary mucinous tumors were positive for enhancement effects. Enhancement effects were observed in all 3 cases of autoimmune-related pancreatitis, but the degree varied. There was a significant correlation between the intensity of enhancement effects and the ratio of patent vessels in the tumors (P < .05). Conclusions. Vascularity was detected by contrast-enhanced sonography in only about half of the ductal carcinomas, confirming the difficulty in distinguishing those tumors from other pancreatic tumors. There was a correlation between the patency of the vessels in the tumors and their vascularity.