Protocol for acquisition of images and measurement of transabdominal ultrasound pancreatic two-dimensional shear wave elastography (2D-SWE).

Abstract

Introduction: Transabdominal ultrasound (TU) pancreatic 2D-SWE elastography is a developing technique that needs to be protocolized.

Objectives: Establish a protocol for image acquisition and measurement of TU pancreatic - 2D-SWE elastography and estimate the minimum number of measurements to be performed.

Materials and methods: Ten measurements of pancreatic elasticity were taken in healthy volunteers using TU-2D-SWE, following a strict protocol for image acquisition and measurement.

Results: The 70% of the participants were women, with an average age, weight, and BMI of 49.5±15.7 years, 65.9±11.9kg, and 24.5±4.2kg/m², respectively. Measurements were taken from the body (70%), tail (16.7%), and pancreatic head (13.3%). The median mean velocity and elasticity were 1.46±0.25cm/sec and 6.46±2.87KPa, respectively. The ROI depth was 4.12±1cm and the SP-ROI distance was 5.2mm on average. There were no statistically significant differences between the 10 measurements. The reliability analysis of the measurements showed high internal consistency and repeatability. Taking 5-6 measurements ensured high concordance with the ten reference measurements. The measurements were significantly lower when the SP-ROI values were intermediate (0.3-0.6cm). The measurement accuracy was higher when performed at a depth less than 4.8cm.

Conclusion: To measure pancreatic elasticity using TU-2D-SWE, we propose a strict protocol for image acquisition and measurement, taking a minimum of 5 measurements in the best visualized and accessible pancreatic portion, and preferably at a depth of less than 4.8cm.