Synthetic axial acquisition-full resolution, low-cost C-scan ultrasonic imaging

The synthetic axial acquisition (SAA) approach presented here is designed to produce C-scan images using low-cost, low bandwidth, front end electronics. We exploit plane wave transmission and shallow C-scan imaging of non-moving, or slowly moving, tissue regions. Between each transmit/receive cycle, the receive sampling trigger is offset by one sampling interval so that over a sequence of acquisitions a sufficiently long data record is synthesized to enable a high-quality approximation to conventional delay and sum beamforming. FIELD II simulations were performed to model the next generation of our sonic window C-scan imaging system using a 5 MHz center frequency, 50% bandwidth, and a 60 X 60 fully sampled two-dimensional (2-D) array with a 0.3-mm element pitch. These simulations, which include analysis of the impact of target motion both parallel and perpendicular to the acoustic beam, indicate that SAA is robust with respect to target motion no faster than 10 mm/s. The impact of electronic noise on SAA also is considered.