Strain ratio vs strain histogram for the elastographic evaluation of non-calcific chronic pancreatitis (CP) ‒ A...

diagnosis of chronic pancreatitis (CP) at early stages remains challenging. Endoscopic ultrasound (EUS) guided strain elastography (SE) has improved the diagnostic yield of CP. The aim of our study was to evaluate the diagnostic yield of SE quantification methods, strain ratio (SR) and strain histogram (SH) to detect non-calcific CP.

a prospective, comparative study was performed with patients undergoing EUS-guided SE for non-calcific CP evaluation. Procedures were performed with linear echoendoscopes. The number of EUS criteria according to the Rosemont classification were evaluated. SH analysis targeted the pancreatic body area, while SR compared this area (A) to a soft extrapancreatic reference area (B), using B/A as the final ratio. Data are shown as percentages and means (95 % CI) and analyzed using ANOVA, linear regression and Spearman tests. Diagnostic accuracy of SR and SH were evaluated using the Rosemont classification as a reference. STARD criteria were followed.

two hundred and eighty-four patients were included (mean age 49.8 years, range 17-85; 142 males). Among them, 43 (15.1 %) had a normal pancreas, 110 (38.7 %) had indeterminate findings, and 131 (46.1 %) had findings suggestive of CP. A SR > 2.42 had a 91.7 % sensitivity and 88.1 % specificity (ROC = 0.968). An SH < 116.1 had an 88.0 % sensitivity and 97.7 % specificity (ROC = 0.964). EUS criteria correlated with pancreatic fibrosis severity by SR (r = 0.785, p < 0.0001) and SH (r = -0.742, p < 0.0001). Age correlated with EUS criteria (r = 0.127, p = 0.03) but not with SE.

the quantification of the degree of pancreatic fibrosis by SR and SH during pancreatic EUS-guided SE had a high diagnostic accuracy for CP and was not influenced by age.