IEEE Trans Med Imaging. 2017 Apr;36(4):878-891. doi: 10.1109/TMI.2016.2644654. Epub 2016 Dec 23.
A novel beamforming technique, named compressed sensing based synthetic transmit aperture (CS-STA) is proposed to speed up the acquisition of ultrasound imaging. This technique consists of three steps. First, the ultrasound transducer transmits randomly apodized plane waves for a number of times and receives the backscattered echoes. Second, the recorded backscattered echoes are used to recover the full channel dataset of synthetic transmit aperture (STA) with a compressed sensing (CS) reconstruction algorithm. Finally, an STA image is beamformed from the recovered full STA dataset. As CS allows recovering a signal from its few linear measurements with high probability, CS-STA is capable of recovering the STA image with fewer firings (i.e., higher frame rate) and retaining the high resolution of STA. In addition, the contrast of the STA image can be improved at the same time owing to the higher energy of plane wave firing in CS-STA. Simulations demonstrate that CS-STA is capable of recovering the STA channel dataset with a smaller number of firings. The performance of CS-STA is evaluated in phantom experiments through comparisons with STA, multi-element STA, conventional focused mode and coherent plane wave imaging. The results demonstrate that, implemented with the same frame rate, CS-STA achieves higher or comparable resolution and contrast. Moreover, comparisons are conducted on the biceps brachii muscle and thyroid of a human subject, and the results demonstrate the feasibility and competitiveness of CS-STA in the in vivo conditions.
提出了一种新的波束形成技术，名为基于压缩感知的合成发射孔径（CS-STA），用于加速超声成像的采集。该技术包括三个步骤。首先，超声换能器发射多次随机变迹的平面波，并接收背散射回波。其次，使用压缩感知（CS）重建算法从记录的背散射回波中恢复全通道的合成发射孔径（STA）数据集。最后，从恢复的全 STA 数据集进行 STA 图像的波束形成。由于 CS 允许以高概率从其少量线性测量中恢复信号，因此 CS-STA 能够以更少的发射次数（即更高的帧率）恢复 STA 图像，并保持 STA 的高分辨率。此外，由于 CS-STA 中的平面波发射具有更高的能量，因此可以同时提高 STA 图像的对比度。模拟结果表明，CS-STA 能够以更少的发射次数恢复 STA 通道数据集。通过与 STA、多元 STA、传统聚焦模式和相干平面波成像进行比较，在体模实验中评估了 CS-STA 的性能。结果表明，在相同帧率下，CS-STA 实现了更高或可比的分辨率和对比度。此外，还在人体肱二头肌和甲状腺上进行了比较，结果表明 CS-STA 在体内条件下具有可行性和竞争力。
