Spatial analysis of cardiac strain using high-frequency four-dimensional ultrasound in mice

Abstract

Cardiac disease remains the number one cause for all mortality in the United States, prompting a continued effort to understand the various factors that exacerbate disease. In this endeavor, mouse models of cardiac disease have served a crucial role by allowing for both investigation of disease factors and longitudinal tracking of cardiac function. Routine assessment of cardiac function in mice can be acquired using high-frequency ultrasound; however, conventional techniques must rely on idealized cardiac geometries to calculate function metrics, as morphometric information is only available from a single plane. Aiming to overcome these limitations, our group has recently developed and validated a high frequency four-dimensional ultrasound (4DUS) technique that provides full volumetric information of the mouse heart synced over one representative cardiac cycle. Analysis of this 4DUS data can provide region-specific wall kinematic information, in contrast to global metrics such as ejection fraction and stroke volume. Preliminary applications of our technique have demonstrated abnormal left-ventricular contractile patterns in mouse models of cardiac hypertrophy, as well as ventricular remodeling in models of myocardial infarction. These initial efforts suggest that widespread adoption of 4DUS has the potential to help increase the amount of information obtained when using mouse models of cardiac disease.