Ultrasonic strain and strain rate imaging for the assessment of regional myocardial function in mice

With high frequency ultrasound systems becoming more widely available, ultrasonic imaging of the murine heart has attracted increasing interest. Typically, standard gray scale imaging has been used to characterize ventricular morphology and function. Prior studies in large animals and humans based on relatively low frequency insonation have shown dial ultrasonic strain and strain rate imaging can be a more sensitive measure of myocardial function. Therefore, in this study, the feasibility of measuring ultrasonic strain and strain rate in the murine heart was tested. Moreover, normal murine strain and strain rate values were established and the ability of these measures to detect abnormal myocardial function was verified. In both mice with normal and abnormal myocardial function the measurement of strain and strain rate was shown to be feasible. Moreover, these cardiac deformation indices were shown to be more sensitive than standard gray scale measurements for the detection of functional abnormalities. Ultrasonic strain and strain rate imaging thus offers a new and more sensitive approach for the non-invasive assessment of murine myocardial function.