Quantitative diagnosis of chronic pancreatitis using EUS elastography

Background: It is difficult to diagnose chronic pancreatitis (CP) objectively because of a lack of standard diagnostic criteria. Endoscopic ultrasonography (EUS) has been used to assess the severity of CP, but the diagnosis of CP using EUS depends on an endosnonographer. The aim of this study was to establish an objective diagnostic method for CP using EUS elastography (EUS-EG). Methods: A retrospective study was designed and 96 patients underwent EUS-EG for follow-up of known CP, or who were clinically suspected as having CP. CP patients were categorized CP patients as 4 stages using the Rosemont classification (RC). EUS-EG was performed and the “Mean value”, which was negatively correlated with pancreatic fibrosis, was calculated using histogram analysis. Results: The “Mean value” of each RC stage (normal, indeterminate for CP, suggestive of CP, and consistent with CP) was 90.1 ± 19.3, 73.2 ± 10.6, 63.7 ± 14.2, and 56.1 ± 13.6, respectively, and showed significant differences for each stage (p < 0.001). There was a significant negative correlation between the “Mean value” and the number of EUS features (r_s = −0.59, p < 0.001). Multiple linear regression analysis was used to assess the diagnostic finding of the “Mean value” and showed that hyperechoic foci with shadowing and lobularity with honeycombing maintained their independent diagnostic findings. Conclusions: EUS-EG was an objective diagnostic apparatus for CP and provided objective information to support EUS features.