光声成像中延迟求和方法和反投影重构方法的比较

Comparison Between Delay and Sum Method and Back-Projection Method in Photoacoustic Tomography

生物组织的光声成像具有高空间分辨率与高对比度的优点,已经成为当前生物医学成像研究的热点课题。目前,延迟求和法和反投影重构法是在光声成像中得到广泛应用的两种重构方法。研究了两种方法各自的成像特点并比较了两者的不同。从频域的观点出发,从理论上分析了两种成像方法的重要区别。试验结果显示,延迟求和法得到的图像平滑,可以清晰地反映出吸收体的内部结构;反投影重构法主要是利用了光声信号的高频成分,能够清晰地分辨出吸收体的边界。研究结果可以为在光声成像的实际应用中选择合适的重构方法提供参考。

Photoacoustic tomography of biological tissue has the advantages of high optical contrast and good spatial resolution, and it has been a currently interesting topic in biological imaging research. Both delay and sum method and back-projection method are extensively used in photoacoustic tomography. The purpose of this study was to experimentally compare the performance of both methods. According frequency-domain analysis, a significant factor that could differentiate them was found. By establishing experiments, the results agreed with the analysis： delay and sum method could provide images where the absorbers are smooth and the details with them could be clearly revealed, and the back-projection method could definitely resolve their boundaries. The results of this study could help to take suit method for reconstruction in practice.