Improvement of ultrasound contrast imaging with adaptive beamformer based on pulse inversion plane wave transmission

Study of ultrasound contrast imaging is of great importance in recent years thanks to its wide application in ultrasonic diagnosis. Plane wave imaging has been considered as a good method with high frame rate and low mechanical index. High frame rate can improve the temporal resolution of contrast imaging. Meanwhile, low mechanical index is essential to contrast imaging since high mechanical index in traditional B-mode imaging could break micro-bubbles easily. However, plane wave contrast imaging suffers from low signal-to-noise ratio (SNR) and contrast (CR) which leads to poor image quality. In this paper, adaptive beamformer and pulse inversion (PO technique were combined to solve the shortcomings of the plane wave contrast imaging. For the adaptive beamformer, eigenspace based minimum variance (ESBMV) with coherence factor (ESBMVCF) was proposed. Experimental results show that ESBMVCF offers an enhancement of 1.1dB, 13dB and 0.8dB in CR, contrast-to-tissue ratio (CTR) and contrast-to-noise ratio (CNR) respectively compared with minimum variance and coherence factor (MVCF). Besides, PI offers 1.5dB, 15dB and 15dB enhancement in CR, CTR and CNR compared with traditional pulse-echo imaging.