High-frequency imaging of intraventricular flow patterns in murine hearts as early indicator of heart failure

Advanced ultrasound vector flow methods for human left ventricle (LV) imaging have the potential to capture subtle deviations from normal cardiac function. However, reducing the complicated flow patterns into more basic predictive quantitative clinical metrics is a major challenge. Murine models make excellent candidates to study human cardiovascular disease and high-frequency ultrasound methods are commonly employed to quantify murine cardiac functional parameters. We have developed a pipeline for multi-angle, plane-wave vector-flow imaging in the murine left ventricle. Using a Verasonics with a 15-MHz array, we demonstrated that LV vorticity patterns were altered in a mouse model with a temperature sensitive arrythmia. We are presently undertaking studies with a mouse model of hypertrophy using a 30-MHz linear array. The increased transmit frequency improves resolution but also increases the likelihood of Doppler aliasing artifacts. A new plane-wave transmit scheme was implemented based on a double transmit combined with a staggered pulse repetition frequency. The ability to de-alias the signal provided unambiguous velocity estimates and resulted in robust final vector flow estimates. A longitudinal study was conducted over 5 months with a mouse model that develops hypertrophy to quantify changes in vector flow parameters between a healthy and disease mouse.