Acoustic radiation force-induced shear wave propagation in cardiac tissue
Shear wave elasticity imaging (SWEI) was employed to track acoustic radiation force (ARF)-induced shear waves in the myocardium of a beating heart. Shear waves were generated in and tracked through the myocardium of the left ventricular free wall (LVFW) in an in vivo heart that was exposed through a thoracotomy; matched studies were also preformed on an ex vivo myocardial specimen. Average shear wave velocities ranged from 2.22 to 2.53 m/s for the ex vivo specimen and 1.5 to 2.9 m/s (1.5-2.09 m/s during diastole; 2.9 m/s during systole) for in vivo specimens. Despite the known rotation of myocardial fiber orientation with tissue depth, there was no statistically significant shear wave velocity depth dependence observed in any of the experimental trials. © 2009 SPIE.
