Ultrasound RF channel data compression for implementation of a software-based array imaging system

Using software for beamforming in ultrasound systems provides high flexibility, and it has been demonstrated that the large amount of computations required in a software-based system can be performed in real time on a personal computer. However, the current bottleneck is in the very high data transfer rate required from the ultrasound front-end to the computer, which generally cannot be achieved without appropriate data compression. Previous studies have examined JPEG compression of ultrasound RF channel data, but the schemes do not exploit temporal redundancy between adjacent frames. This study utilized MPEG to process the ultrasound RF data in order to increase the compression efficiency. Our results indicate that the compression ratio of MPEG under the 5 μm interframe displacement is smaller than 0.13 and meets the real-time data transfer requirement. The MPEG generally provides a better compression ratio than does JPEG, and the compressed data size reduced at least 38% than JPEG when the interframe displacement is 5 μm. Moreover, the compression efficiency for motions in different directions is highly dependent on the frame-to-frame correlation.