Mueller矩阵成像法可用于获取生物组织的微观结构信息, 在组织早期癌变的诊断中发挥着重要作用。采用不同的成像方式得到的结果往往具有很大的差异。为了保证Mueller矩阵成像法对组织癌变诊断结果的可靠性, 需要明确成像方式不同对检测结果的影响。建立了正常和癌变上皮组织散射模型, 利用Monte Carlo仿真法对比研究了癌变对上皮组织前向和后向散射特性的影响。仿真结果表明, 采用前向散射成像方式时, 去偏参量对组织状态的改变比较敏感, 但去偏参量随组织癌变的发展并非单调变化; 而采用后向散射成像方式时, 相位延迟参量随组织状态的改变有显著变化, 且相位延迟随组织癌变的发展单调减小。

Mueller matrix imaging can be used to obtain microstructure information of biological tissues, and plays an important role in the diagnosis of precancer. The results obtained by different imaging geometry may have significant difference to each other. To ensure the realibility of Mueller matrix imaging in the diagnosis of cancerous tissue, it is necessary to have a clear cognition of the influence of imaging geometry on the measurement results. The models of normal and cancerous epithelial tissues are established, and the effects of canceration on forward and backward scattering characteristics of epithelial tissues are analyzed by Monte Carlo simulation method. The simulation results show that it is depolarization that is sensitive to tissue state changes when imaging with forward scattering photons, but depolarization does not change monotonically. However, retardance of different tissues has a significant change when imaging with backscattering photons, and backward scattering retardance decreases gradually with the development of canceration.