Endoscopic ultrasound elastography in solid pancreatic lesions: individual and combined performance of strain ratio, fat-lesion strain ratio, and mean strain histogram for diagnosing pancreatic ductal adenocarcinoma

This study aims to compare three different elastography parameters to evaluate their efficacy in diagnosing Pancreatic Ductal Adenocarcinoma (PDAC) and provide a semi-quantitative or quantitative assessment method for endoscopic ultrasound elastography. We retrospectively analyzed patients with PDAC, patients with benign pancreatic diseases, and individuals with normal pancreas who underwent endoscopic ultrasound elastography at the First Affiliated Hospital of Xi'an Jiaotong University between June 2022 and March 2023. Elastography parameters collected included strain ratio (SR), fat-lesion strain ratio (FLR), and mean strain histogram value (MEAN). Overall, 102 patients were enrolled, comprising 74 patients with PDAC (malignant group), 15 patients with benign lesions, and 13 patients with normal pancreas. Based on the median values, parameters were categorized into different groups for SR, FLR, and MEAN. A significant difference in the distribution between benign and malignant pancreatic lesions was observed across the groups (P < 0.001). ROC curve analysis for diagnosing PDAC across all study subjects showed that when SR > 15.55, FLR > 9.16, and MEAN < 23.85, the lesion area exhibited relatively lower elasticity and greater stiffness, indicating a higher likelihood of PDAC. After excluding normal pancreatic tissue, the study found that when SR > 19.145, FLR > 9.16, and MEAN < 16.25, it was easier to screen for PDAC among patients with pancreatic disease. Further combined analysis of the different parameters revealed that the combined use of the three parameters offered greater advantages in enhancing diagnostic performance. The study reveals that the strain ratio (SR), fat-lesion strain ratio (FLR), and mean strain histogram value (MEAN) are closely related to the characteristics of pancreatic diseases. SR exhibited the highest diagnostic efficacy for PDAC, and combining multiple parameters further improved diagnostic accuracy. Patients with pancreatic disease whose SR > 19.145, FLR > 9.16, and MEAN < 16.25 are more likely to be identified as PDAC.