Lu Shukuan, Shi Aiwei, Jing Bowen, Du Xuan, Wan Mingxi
The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China.
The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Department of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China.
Ultrason Sonochem. 2017 Nov;39:291-300. doi: 10.1016/j.ultsonch.2017.03.060. Epub 2017 Apr 28.
Cavitation erosion in blood vessel plays an important role in ultrasound thrombolysis, drug delivery, and other clinical applications. The controllable superficial vessel erosion based on ultrasonic standing wave (USW) has been used to effectively prevent vessel ruptures and haemorrhages, and optical method is used to observe the experiments. But optical method can only work in transparent media. Compared with standard B-mode imaging, passive acoustic mapping (PAM) can monitor erosion in real time and has better sensitivity of cavitation detection. However, the conventionally used PAM has limitations in imaging resolution and artifacts. In this study, a unique PAM method that combined the robust Capon beamformer (RCB) with the sign coherence factor (SCF) was proposed to monitor the superficial vessel erosion in real time. The performance of the proposed method was validated by simulations. In vitro experiments showed that the lateral (axial) resolution of the proposed PAM was 2.31±0.51 (3.19±0.38) times higher than time exposure acoustics (TEA)-based PAM and 1.73±0.38 (1.76±0.48) times higher than RCB-based PAM, and the cavitation-to-artifact ratio (CAR) of the proposed PAM could be improved by 22.5±3.2dB and 7.1±1.2dB compared with TEA and RCB-based PAM. These results showed that the proposed PAM can precisely monitor the superficial vessel erosion and the erosion shift after USW modulation. This work may have the potential of developing a useful tool for precise spatial control and real-time monitoring of the superficial vessel erosion.
血管中的空化侵蚀在超声溶栓、药物递送及其他临床应用中发挥着重要作用。基于超声驻波（USW）的可控浅表血管侵蚀已被用于有效预防血管破裂和出血，并且采用光学方法来观察实验。但光学方法仅适用于透明介质。与标准B模式成像相比，被动声学映射（PAM）能够实时监测侵蚀情况，并且具有更好的空化检测灵敏度。然而，传统使用的PAM在成像分辨率和伪像方面存在局限性。在本研究中，提出了一种独特的PAM方法，该方法将稳健的Capon波束形成器（RCB）与符号相干因子（SCF）相结合，以实时监测浅表血管侵蚀。通过仿真验证了所提方法的性能。体外实验表明，所提PAM的横向（轴向）分辨率比基于时间曝光声学（TEA）的PAM高2.31±0.51（3.19±0.38）倍，比基于RCB的PAM高1.73±0.38（1.76±0.48）倍，并且所提PAM的空化与伪像比（CAR）与基于TEA和RCB的PAM相比可分别提高22.5±3.2dB和7.1±1.2dB。这些结果表明，所提PAM能够精确监测浅表血管侵蚀以及超声驻波调制后的侵蚀偏移。这项工作可能具有开发一种用于精确空间控制和实时监测浅表血管侵蚀的有用工具的潜力。
