Age-related changes in pancreatic elasticity: When should we be concerned about their effect on strain elastography?

Background: Ultrasound strain elastography is one of the useful methods for evaluating pancreatic lesions. During aging, several pancreatic parenchymal changes occur that may interfere with the interpretation of the ultrasound images. We studied age-related changes in pancreatic elasticity using transabdominal ultrasound strain elastography in subjects without known pancreatic disease. Methods: This study was conducted at Nagoya University Hospital, which is an academic medical center, and included 102 subjects (66 women and 39 men) aged 20-85 years (mean 58.6 ± 17.5) who underwent transabdominal ultrasonography for screening and follow-up for non-pancreatic diseases. Strain elastography of the pancreas was performed, and the results were subjected to quantitative strain histogram analysis. The correlations of age with four elastographic parameters (Mean, Standard deviation, Skewness, and Kurtosis) and other findings, including hyperechoic pancreas, hyperechoic liver, and diabetes, were evaluated. Results: There was a significant correlation between increasing age and elastographic parameters such as the Mean (P = 0.004), Skewness (P = 0.007), and Kurtosis (P = 0.03), and these differences became significant after the age of 40. The prevalence of hyperechoic pancreas increased with age (P < 0.001), and the Means were lower in those with hyperechoic pancreas (P = 0.004) and a higher body mass index (BMI, P = 0.008). No significant correlations with diabetes, hyperechoic liver, or elastographic parameters were demonstrated. Conclusion: Strain elastography demonstrated elastographic changes in the pancreas with aging that included a decreasing Mean and increasing Skewness and Kurtosis after the age of 40. The prevalence of pancreatic hyperechogenicity increased, and the pancreatic hyperechogenicity was significantly negatively correlated with the Mean.