Small pancreatic ductal carcinomas on triple-phase contrast-enhanced computed tomography: enhanced rims and the pathologic correlation

Purpose To reveal the prevalence of small (≤ 20 mm) pancreatic ductal carcinomas with enhanced rims on triple-phase contrast-enhanced CT and correlate the CT images with the pathologic findings. Materials and methods Between April 2005 and April 2016, 45 patients underwent preoperative triple-phase contrast-enhanced CT and were pathologically diagnosed with small pancreatic ductal carcinoma. CT images were independently reviewed by two radiologists. The attenuation values of the enhanced rims, internal areas of the tumors, and surrounding pancreatic parenchyma were compared using Mann–Whitney U test. These areas were also correlated with the pathologic findings. Tumor invasiveness was compared between the tumors with and without enhanced rims using Fisher’s exact test. Results Enhanced rims were identified in 18 tumors (40%) by consensus between the two reviewers. The enhanced rims showed significantly higher mean attenuation values compared with the internal areas of the tumors ( p