STRAIN ESTIMATION OF THE MURINE RIGHT VENTRICLE USING HIGH-FREQUENCY SPECKLE-TRACKING ULTRASOUND

Right ventricular (RV) strain measurements from ultrasound via speckle-tracking techniques are being used more frequently as a non-invasive diagnostic tool for a variety of cardiopulmonary pathologies. However, despite the clinical utility of ultrasound RV strain measurements, quantification of RV strain in rodents remains difficult owing to unique image artifacts and non-standardized methodologies. We demonstrate here a simple approach for measuring RV strain in both mice and rats using high-frequency ultrasound and automated speckle tracking. Our results show estimated peak RV free-wall longitudinal strain values (mean +/- standard error of the mean) in mice (n = 15) and rats (n = 5) of, respectively, -10.38% +/- 0.4% and -4.85% +/- 0.42%. We further estimated the 2-D Green-Lagrange strain within the RV free wall, with longitudinal components estimated at -5.7% +/- 0.48% in mice and -2.1% +/- 0.28% in rats. These methods and data may provide a foundation for future work aimed at evaluating murine RV strain levels in different disease models. (C) 2021 World Federation for Ultrasound in Medicine & Biology. All rights reserved.