Synthetic aperture (SA) ultrasound imaging provides accurate axial and lateral displacement estimates, however, the low transmit acoustic power of SA limits its clinical use. In this paper, we investigated the feasibility of using multi-element sub-aperture to improve acoustic power of SA imaging for carotid artery elastography. We used Field II to synthesize RF images with varying size sub-apertures, at different opening angles. Axial and lateral displacements were estimated by applying the 2D cross-correlation tracking algorithm to the synthesized RF images. Performance was assessed by computing root mean square error (RMSE) between the theoretical and estimated elastograms. A noticeable increase in power was observed for a configuration involving 3 -11 elements in the sub-aperture and an opening angle between 60°– 120°, respectively. More specifically, RMSE of axial and lateral displacements was less than 0.4% and 2%, respectively, and whereas in the case of radial and circumferential strain was less than 2% and 7%, respectively. These findings were encouraging enough to warrant further studies.

Date Published: 29 March 2013
PDF: 10 pages
Proc. SPIE 8675, Medical Imaging 2013: Ultrasonic Imaging, Tomography, and Therapy, 86750I (29 March 2013); doi: 10.1117/12.2007214

Published in SPIE Proceedings Vol. 8675:
Medical Imaging 2013: Ultrasonic Imaging, Tomography, and Therapy
Johan G. Bosch; Marvin M. Doyley, Editor(s)