Efficacy of quantitative analysis for differentiating pancreatic solid lesions using contrast-enhanced endoscopic ultrasonography

Aim: To evaluate the efficacy of quantitative analysis for differentiating pancreatic ductal adenocarcinoma (PDAC) and inflammatory pancreatic masses (IPM) using time intensity curve (TIC) analysis based on contrast-enhanced endoscopic ultrasonography (CE-EUS). Methods: We reviewed 89 patients who had undergone CE-EUS for pancreatic solid lesions at our department between August 2012 and January 2016. CE-EUS images were recorded for 2 minutes after injection of the contrast agent. The diagnostic abilities of the enhanced patterns and TIC analysis were assessed. Results: The enhanced patterns of PDAC were mainly hypovascular and heterogeneous (66/77), while IPM were mainly isovascular and homogeneous (6/12). In PDAC, sensitivity was 77.9%, specificity 83.3%, and accuracy was 78.7%. In TIC analysis, the intensity reduction rate was significantly different at 10 and 30 seconds after peak intensity. After creating a cutoff value (49%) based on the receiver operating characteristic curve for the intensity reduction rate after 30 seconds, diagnosing PDAC with TIC analysis had a sensitivity of 67.5%, specificity of 100%, and accuracy of 71.9%. Combining enhanced pattern analysis with TIC analysis had a sensitivity of 90.9%, pecificity of 83.3%, and accuracy of 89.9%. Conclusion: Combining TIC analysis with CE-EUS improved diagnostic accuracy when differentiating between PDAC and IPM.