Papers Published

1. Bouchard, RR; Hsu, SJ; Wolf, PD; Trahey, GE, In vivo cardiac, acoustic-radiation-force-driven, shear wave velocimetry., Ultrasonic Imaging, vol. 31 no. 3 (July, 2009), pp. 201-213 [19771962], [doi] .
   (last updated on 2023/06/01)

   Abstract:
   Shear wave elasticity imaging (SWEI) was employed to track acoustic radiation force impulse (ARFI)-induced shear waves in the mid-myocardium of the left ventricular free wall (LVFW) of a beating canine heart. Shear waves were generated and tracked with a linear ultrasound transducer that was placed directly on the exposed epicardium. Acquisition was ECG-gated and coincided with the mid-diastolic portion of the cardiac cycle. Axial displacement profiles consistent with shear wave propagation were clearly evident in all SWEI acquisitions (i.e., those including an ARFI excitation); displacement data from control cases (i.e., sequences lacking an ARFI excitation) offered no evidence of shear wave propagation and yielded a peak absolute mean displacement below 0.31 microm after motion filtering. Shear wave velocity estimates ranged from 0.82 to 2.65 m/s and were stable across multiple heartbeats for the same interrogation region, with coefficients of variation less than 19% for all matched acquisitions. Variations in velocity estimates suggest a spatial dependence of shear wave velocity through the mid-myocardium of the LVFW, with velocity estimates changing, in limited cases, through depth and lateral position.