Abstract:
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 D, linear retardance δ, and depolarization Δ 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 D 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.
摘要:
穆勒矩阵包含了丰富的介质微观甚至纳米结构信息。尤其是,它可以作为定量表征各向异性结构的有力工具,比如颗粒大小,密度,和样品中纤维的取向信息。与非偏振显微成像技术相比,穆勒矩阵显微镜还可以从低分辨率的衍生参数图像中获得有关样品的一些基本结构信息。这里,为了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,使用一系列放大倍数或物镜的数值孔径(NA)值,测量富含胶原纤维的未染色的大鼠背侧皮肤组织切片的显微镜Mueller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,Mueller矩阵的极坐标分解参数离散度D,线性延迟δ,使用低NA物镜获得的去极化Δ图像保留了样品的大部分结构信息,并且可以提供快速的成像速度。此外,基于圆柱散射体的散射相函数分析和蒙特卡罗模拟表明,不同成像分辨率的双衰减参数D图像有望用于区分不同粒径介质中的纤维散射体。这项研究提供了一个标准,以决定使用具有低NA目标的透射Mueller矩阵显微镜可以准确,快速地获得哪些结构信息,以协助病理诊断和其他应用。