Qiu Weibao, Wang Xingying, Chen Yan, Fu Qiang, Su Min, Zhang Lining, Xia Jingjing, Dai Jiyan, Zhang Yaonan, Zheng Hairong
IEEE Trans Biomed Eng. 2017 Aug;64(8):1935-1942. doi: 10.1109/TBME.2016.2631224. Epub 2016 Nov 22.
Advances in methodologies and tools often lead to new insights into cardiovascular diseases. Intravascular ultrasound (IVUS) is a well-established diagnostic method that provides high-resolution images of the vessel wall and atherosclerotic plaques. High-frequency (>50 MHz) ultrasound enables the spatial resolution of IVUS to approach that of optical imaging methods. However, the penetration depth decreases when using higher imaging frequencies due to the greater acoustic attenuation. An imaging method that improves the penetration depth of high-resolution IVUS would, therefore, be of major clinical importance. Modulated excitation imaging is known to allow ultrasound waves to penetrate further. This paper presents an ultrasound system specifically for modulated-excitation-based IVUS imaging. The system incorporates a high-voltage waveform generator and an image processing board that are optimized for IVUS applications. In addition, a miniaturized ultrasound transducer has been constructed using a Pb(MgNb)O-PbTiO single crystal to improve the ultrasound characteristics. The results show that the proposed system was able to provide increases of 86.7% in penetration depth and 9.6 dB in the signal-to-noise ratio for 60 MHz IVUS. In vitro tissue samples were also investigated to demonstrate the performance of the system.
方法学和工具的进步常常带来对心血管疾病的新见解。血管内超声（IVUS）是一种成熟的诊断方法，可提供血管壁和动脉粥样硬化斑块的高分辨率图像。高频（>50 MHz）超声使IVUS的空间分辨率接近光学成像方法。然而，由于更大的声衰减，使用更高成像频率时穿透深度会降低。因此，一种能提高高分辨率IVUS穿透深度的成像方法将具有重要的临床意义。已知调制激励成像能使超声波穿透得更远。本文介绍了一种专门用于基于调制激励的IVUS成像的超声系统。该系统集成了针对IVUS应用进行优化的高压波形发生器和图像处理板。此外，使用Pb（MgNb）O-PbTiO单晶构建了小型化超声换能器以改善超声特性。结果表明，对于60 MHz的IVUS，所提出的系统能够使穿透深度增加86.7%，信噪比提高9.6 dB。还对体外组织样本进行了研究以证明该系统的性能。
