用于血管内成像的60 MHz高频超声换能器设计及其成像实验

60 MHz High Frequency Intravascular Ultrasound Transducer and in vivo Imaging

在血管内超声成像系统中,超声换能器是重要的部件之一,对成像性能起决定性作用。提高超声换能器的成像分辨率可以获得更多图像细节,有助于临床获取动脉粥样硬化斑块的细节信息。此外,超声换能器还需要具有足够的穿透深度,能够对斑块和血管进行完整评估。而成像分辨率和成像深度都与超声换能器的频率密切相关,且二者相互制约。该文综合考虑了冠脉成像对成像分辨率与成像深度的要求,优化设计并制备了一种60 MHz的微型高频换能器。仿体实验表明,基于该换能器的超声成像分辨率可显著提高,且成像深度满足冠脉成像的需求。大动物活体实验结果表明,与商业40MHz换能器相比,该文所设计的换能器能更清楚地看到血管中膜内层边界和支架结构,可以为临床提供更精细的指导优化。

Ultrasound transducer is one of the most critical components in the intravascular ultrasound imaging systems and plays a decisive role in imaging performance. Since it is vital to obtain detailed information on atherosclerotic plaques in clinical, it is important to enhance the imaging resolution.Additionally, it is indispensable to achieve sufficient penetration depth for the complete assessment of plaque and blood vessels. The center frequency of the transducer determines the ultrasound imaging resolution and penetration depth, which are restricted by each other. In this paper, a 60 MHz miniature highfrequency transducer is carefully designed and fabricated to meet the coronary artery imaging requirements for imaging resolution and depth. The phantom experiments show that the transducer proposed in this paper can provide high-resolution imaging with the imaging depth meeting the needs of coronary imaging. In vivo experiment of large animals shows that, compared with commercial 40 MHz transducers, the transducer designed in this paper can image the vascular media intima and stent structure more clearly, which can provide more precise guidance for clinical practice.