Shear wave elastography in healthy patients: Pancreatic stiffness is less reliable than liver and spleen measurements

BACKGROUND Shear wave elastography (SWE) is a non-invasive ultrasound-based technique used to assess tissue stiffness, which reflects underlying pathological changes. While SWE has been widely applied for liver fibrosis evaluation, its application to other abdominal organs, such as the spleen and pancreas, is gaining interest. However, normal stiffness values and inter-system agreement remain poorly defined. AIM To assess the feasibility and agreement of liver, spleen, and pancreas stiffness using three SWE methods. METHODS This single-center observational study enrolled 50 healthy adult volunteers. Liver, spleen, and pancreas stiffness were assessed using three SWE methods: Point-SWE (p-QElaXto) and 2-Dimensional-SWE (2D-QElaXto) with Esaote MyLab 9, and 2D-SWE with SuperSonic Imagine. Feasibility, inter-operator reproducibility, and concordance among systems were evaluated. Stiffness was expressed as median kPa values, and technical reliability was assessed using the interquartile range/median ratio and stability index thresholds. RESULTS Liver and spleen stiffness assessment was feasible in > 98% of patients, while pancreas stiffness was measurable in 84%-88% depending on the SWE technique. Mean liver stiffness ranged between 3.9-4.7 kPa across techniques, spleen stiffness ranged from 19.4-23.0 kPa, and pancreas stiffness from 5.2-7.6 kPa. Inter-operator agreement was excellent for liver (intraclass correlation coefficient > 0.90) and good to moderate for spleen and pancreas (intraclass correlation coefficient from 0.43 to 0.90). Bland-Altman analysis confirmed good correlation but also systematic differences among devices, especially in pancreas measurements. CONCLUSION This is the first study to establish normal liver, spleen, and pancreas stiffness using MyLab 9 SWE integrated methods as compared to SuperSonic Imagine, with acceptable inter-technique agreement. Liver and spleen values matched existing guidelines; pancreas SWE showed more variability and reduced reproducibility.