基于相干因子的高斯加权合成孔径聚焦技术的光声信号处理

Photoacoustic Signal Processing with Gaussian Weighted Synthetic Aperture Focusing Technique Based on Coherence Factor

光声成像是近年来快速发展的一种新型医学成像技术,具有分辨率高、对比度好、无电离辐射等优点,为多种组织以及细胞成像提供了一种有力的成像工具和检测手段。其中光声显微成像具有高分辨率,可达微米级。因为光声显微成像采用点对点扫描方式,使得光声显微成像图像质量依赖于光声信号质量。由于存在背景噪声等因素,光声信号质量受到严重影响,因此需要对检测到的光声信号进行去噪处理。本文在合成孔径聚焦技术基础上进行改进,提出了高斯加权合成孔径聚焦技术,并采用相干因子对合成后信号进行加权处理。实验得出相干因子的高斯加权合成孔径聚焦技术相较于传统合成孔径聚焦技术能够更好地减少背景噪声,提高信噪比从而提高重构图像质量。

Photoacoustic imaging is a new medical imaging technology which has developed rapidly in recent years.It has the advantages of high resolution,good contrast,and no ionizing radiation.It provides a powerful imaging tool and detection method for various tissue and cell imaging.Among them,photoacoustic microscopy imaging(PAM)has a high resolution and can reach the micron level.Because the PAM adopts a point-to-point scanning method,the image quality of the PAM depends on the quality of the photoacoustic signal.Due to factors such as background noise,the quality of photoacoustic signals is seriously affected.So it is necessary to denoise the detected photoacoustic signals.In this paper,based on the synthetic aperture focusing technology,a Gaussian weighted synthetic aperture focusing technology and coherence were proposed to weight the synthesized signal.The results showed that the Gaussian weighted synthetic aperture focusing method with coherence factor can better reduce the background noise and improve the signal-to-noise ratio compared with the traditional synthetic aperture focusing technology thereby improving the quality of the reconstructed images.