模拟微血管的光声成像技术研究

Photoacoustic Tomography for Micro-blood Vessel

目的:为了实现较深层组织内微血管的光声成像。方法:采用波长532nm、重复频率10Hz的脉冲激光作为激励源,宽带非聚焦针状探头以圆周扫描的方式采集时域光声信号,二维光学吸收分布图像由时域后向投影算法重建,以线扩展函数为依据测量系统的成像空间分辨率。结果:成像空间分辨率0.1mm,模拟微血管网络的光声图像与原始样品完全吻合。结论:对组织内癌症病灶的早期诊断具有较大的意义。

Objectieve： In order to get the photoacoustic （PA） image of micro-blood vessel deep inside biological tissue. Materials and Methods： A 532nm pulse laser with the repetition rate of 10Hz was used as the pumping source. A wide band unfocused needle ultrasound transducer was used to collect time-domain PA signal of the tissue-mimicking phantom by circular scan. The 2D optical absorption image was reconstructed by time-domain spherical back projection algorithm. The spatial resolution was measured by line-spread-fimction（LSF）. Results：The experimental results demonstrated that the spatial resolution was 0. lmm and the PA image of the micro-vascular network agreed well with the tissue-mimicking phantom. Conclusion： The proposed method is valuable for the diagnosis of early cancer inside tissue.