Shao Conghui, Chen Binguo, He Honghui, He Chao, Shen Yuanxing, Zhai Haoyu, Ma Hui
Department of Physics, Tsinghua University, Beijing, China.
Guangdong Research Center of Polarization Imaging and Measurement Engineering Technology, Shenzhen Key Laboratory for Minimal Invasive Medical Technologies, Institute of Optical Imaging and Sensing, Shenzhen International Graduate School, Tsinghua University, Shenzhen, China.
Front Chem. 2022 Jul 12;10:936255. doi: 10.3389/fchem.2022.936255. eCollection 2022.
The Mueller matrix contains abundant micro- and even nanostructural information of media. Especially, it can be used as a powerful tool to characterize anisotropic structures quantitatively, such as the particle size, density, and orientation information of fibers in the sample. Compared with unpolarized microscopic imaging techniques, Mueller matrix microscopy can also obtain some essential structural information about the sample from the derived parameters images at low resolution. Here, to analyze the comprehensive effects of imaging resolution on polarization properties obtained from the Mueller matrix, we, first, measure the microscopic Mueller matrices of unstained rat dorsal skin tissue slices rich in collagen fibers using a series of magnifications or numerical aperture (NA) values of objectives. Then, the first-order moments and image texture parameters are quantified and analyzed in conjunction with the polarization parameter images. The results show that the Mueller matrix polar decomposition parameters diattenuation , linear retardance , and depolarization images obtained using low NA objective retain most of the structural information of the sample and can provide fast imaging speed. In addition, the scattering phase function analysis and Monte Carlo simulation based on the cylindrical scatterers reveal that the diattenuation parameter images with different imaging resolutions are expected to be used to distinguish among the fibrous scatterers in the medium with different particle sizes. This study provides a criterion to decide which structural information can be accurately and rapidly obtained using a transmission Mueller matrix microscope with low NA objectives to assist pathological diagnosis and other applications.
穆勒矩阵包含了介质丰富的微观乃至纳米结构信息。特别是，它可作为一种强大工具来定量表征各向异性结构，比如样品中纤维的粒径、密度和取向信息。与非偏振显微成像技术相比，穆勒矩阵显微镜还能在低分辨率下从导出的参数图像中获取有关样品的一些基本结构信息。在此，为分析成像分辨率对从穆勒矩阵获得的偏振特性的综合影响，我们首先使用一系列物镜放大倍数或数值孔径（NA）值来测量富含胶原纤维的未染色大鼠背部皮肤组织切片的微观穆勒矩阵。然后，结合偏振参数图像对一阶矩和图像纹理参数进行量化和分析。结果表明，使用低NA物镜获得的穆勒矩阵偏振分解参数二向色性、线性延迟和退偏图像保留了样品的大部分结构信息，并且能提供快速成像速度。此外，基于圆柱形散射体的散射相函数分析和蒙特卡罗模拟表明，不同成像分辨率下的二向色性参数图像有望用于区分介质中不同粒径的纤维状散射体。本研究提供了一个标准，用于确定使用低NA物镜的透射式穆勒矩阵显微镜能准确快速获取哪些结构信息，以辅助病理诊断及其他应用。
