基于阵列式换能器的光声成像系统的实现

Implementation of a Photoacoustic Imaging System Based on Array Transducer

目的:本文设计了一套光声成像(photoacoustic imaging,PAI)系统,由脉冲激光、阵列换能器、临床超声(ultrasound,US)主机、软件平台以及成像样品组成。系统的图像质量、最大成像深度等重要参数需通过实验进行确定。方法:使用本系统对黑色头发丝横截面进行成像,比较、分析光声(photoacoustic,PA)信号幅值的半极大处全宽度以量化图像分辨率。此外,使用系统对特定的光吸收体和鸡胸肉组织进行成像,确定系统的成像深度。结果:实验结果证明了PAI系统的实现,其PA图像的平均轴向和横向分辨率分别约为0.18 mm和1.44mm,系统的最大成像深度达到4.6 cm。结论:本PAI系统PA图像分辨率优于US主机获得的US图像分辨率,系统最大成像深度与其他国际研究组的系统成像深度的数量级一致。通过进一步优化与活体组织实验的开展,本PAI系统将有望实现临床成像诊断。

Objective： This paper designs a photoacoustic imaging （PAI） system with a pulsed laser, clinical ultra- sound （US） machine, array- transducer, software platform and imaging samples. Key parameters, such as image resolu- tion and maximum imaging depth, are supposed to be addressed. Methods ： We imaged the cross section of the human black hair with our PAI system. To quantify- the photoaeoustie （PA） image resolution, full width at half maximum of the profile of PA signal amplitude has been analyzed. In addition, to determine the imaging depth of the system, we imaged an optical absorber with chicken breast tissue. Results ： The results justified the implementation of the PAI system. The average axial and lateral resolution were - 0.18 and - 1.44 mm. The imaging depth of the system reached - 4.6 em. Conclusion ： The image resolution of PAI system is better than US image of US machine. The maximum imaging depth of the system shared the same order of magnitude as other pioneering international studies. The system is promising for fur- ther researches and clinical imaging.