A new synthetic aperture imaging method using virtual elements on both transmit and receive

The research for improving the performance of the beamformer in a medical ultrasound imaging system while maintaining the hardware complexity properly has been steadily going on. One example of such research is the synthetic aperture sequential beamforming. This method uses fixed-point receive focusing and all-point transmit focusing through synthetic aperture imaging. Thus, the hardware complexity is greatly reduced in this method, but the performance of this method is similar to that of the conventional B-mode imaging that uses dynamic receive focusing and fixed-point transmit focusing. In this paper, we propose a novel full virtual synthetic aperture imaging method which improves the performance of the synthetic aperture sequential beamforming in terms of the lateral resolution and signal-to-noise ratio. We found that many fixed-point receive focusing blocks working in parallel can be regarded as virtual receive elements and that dynamic receive focusing can be done with these virtual receive elements. We achieve performance improvement by employing this dynamic receive focusing in the proposed method. The efficacy of the proposed method is verified through the Field II simulation.