全场低帧率光学微血管造影成像

Full-field optical micro-angiography with low frame rate

针对传统激光多普勒成像空间分辨率不高的问题,根据动态散射信号和静态散射信号在频谱的不同分布特性,提出一种全场低帧率光学血管造影成像技术。通过采用低帧率-短曝光的采样模式获取散射光信号,保证相机有足够的像素得到全场高空间分辨率图像;对粒子的时域信号进行傅立叶变换,选取归一化功率谱零阶矩为成像参量,实现了模拟血红细胞的浓度成像。对活体玻璃猫鱼成像实验表明,微血管脉络造影的空间分辨率达60μm,证明了本方法用于微血管造影成像的可行性。与眼底照相机相结合,其有望发展为一种实用的无需造影剂的眼底微血管造影成像技术。

In view of the traditional laser Doppler′s low spatial resolution,based on different distribution characteristics between static and dynamic scattering signals in spectrum,this paper proposes a full-field optical micro-angiography with low frame rate.The technique uses the sampling mode with low frame rate and short time exposure to capture scattering signal,and ensure enough pixels to obtain a full-field high spatial resolution image.The concentration image of blood erythrocytes phantom is realized through performing Fourier transform to the time domain signal of particles and calculating the zero-moment of spectral power density as the imaging parameters.In vivo experiments on GlassCatfish verify that this method is capable of providing a high-spatial-resolution microvessel map within 60μm.With a fundus camera,this technique is potential to develop a label-free full-field fundus optical angiography.