Intra-Observer Reproducibility of Endoscopic Ultrasound Point Shear-Wave Elastography: A 120-Patient Prospective...

Background and Objectives: Endoscopic ultrasound point shear-wave elastography (EUS-pSWE) bypasses subcutaneous fat and may provide weight-independent liver stiffness measurements; however, data on reproducibility and quality criteria remain limited. This study aimed to evaluate the intra-observer reproducibility and short-term variability of EUS-pSWE. Materials and Methods: In this single-center prospective cohort study (December 2024-February 2025), 120 consecutive adults undergoing diagnostic EUS were enrolled. For each hepatic lobe, 10 consecutive measurements were obtained and grouped into two sequential blocks of five measurements without scope repositioning. Intra-observer reproducibility was assessed using intraclass correlation coefficients (ICC3,1). The agreement between acquisition runs and determinants of short-term variability was also evaluated. Same-day vibration-controlled transient elastography (VCTE) served as an external comparator. Results: Forty-six participants were obese (BMI ≥ 30 kg/m²). The mean VCTE stiffness was 6.24 kPa, while the mean EUS-pSWE stiffness was 9.40 ± 5.64 kPa. Among examinations meeting IQR/Median < 30% quality criteria, reproducibility was excellent (left ICC 0.97 [0.95-0.98]; right ICC 0.92 [0.86-0.95]) and consistent across BMI strata. EUS-pSWE correlated strongly with VCTE (r = 0.81, p < 0.001). In contrast, agreement between consecutive acquisition runs was low, indicating increased short-term variability. EUS-pSWE quality pass rates based on IQR/Median criteria were modest (left 56.7%, right 41.7%, both lobes 23.3%), although all measurements fulfilled device-specific validity criteria (VSN > 60%). Age and BMI were not significant predictors of variability. Conclusions: EUS-pSWE demonstrates excellent intra-observer reproducibility under quality-controlled conditions and shows a strong correlation with VCTE. However, short-term variability between acquisition runs and limited feasibility based on conventional quality thresholds should be considered. EUS-pSWE appears to be a promising modality for liver stiffness assessment, warranting further validation of quality criteria and clinical thresholds.