基于阵列探测方式的时域光声成像系统

Time Domain Photoacoustic Tomography System Using Linear Transducer Array

将阵列超声探头和超声相控技术与光声成像相结合的成像系统,与采用水听器的单探头旋转扫描光声成像系统相比,避免了机械旋转机构给光声信号采集所带来的不稳定性,提高了数据采集速度.时域光声信号由64阵元线阵超声探头以电子相控聚焦的方式进行线性扫描采集,然后通过时域后向投影算法进行光声图像的重建.采用波长532nm、重复频率10Hz的脉冲激光,系统可快速重建样品内部光学吸收分部的二维图像,单帧图像数据采集时间小于200s,成像横向分辨率小于2mm.实验结果表明,采用此方法可显著提高系统对光声信号的扫描稳定性和成像效率,该系统是一种有潜在临床应用价值的光声成像系统.

A system which combines photoacoustic （PA） tomography with ultrasonic phase control technique is developed. Compared with the PA tomography using a single rotating transducer, the system has avoided the instability of signal brought by the mechanical rotating system and the data acquisition speed has been improved. Time domain PA signal was acquired by linear ultrasonic transducer array containing 64 transducer element under the control of electronic phase control and focusing circuit, the PA image was then reconstructed by time domain back projection algorithm. Using 532 nm pulsed laser with the repetition rate of 10 Hz as a pumping source, the system can rapidly reconstruct the 2D optical absorption image inside phantom, the data acquisition time of a single frame of PA image is less than 200 s and the lateral resolution is less than 2 mm. The experiment shows that the method can greatly improve the scanning stability and the efficiency of PA image reconstruction and has the potential application value in clinic.