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 μm 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.
Original language | English (US) |
---|---|
Pages (from-to) | 201-213 |
Number of pages | 13 |
Journal | Ultrasonic Imaging |
Volume | 31 |
Issue number | 3 |
DOIs | |
State | Published - Jul 2009 |
Externally published | Yes |
Keywords
- Acoustic radiation force
- Cardiac imaging
- Myocardium
- Shear wave velocimetry
- Ultrasound
ASJC Scopus subject areas
- Radiological and Ultrasound Technology
- Radiology Nuclear Medicine and imaging