Yang Defu, Chen Xueli, Peng Zhen, Wang Xiaorui, Ripoll Jorge, Wang Jing, Liang Jimin
School of Life Science and Technology, Xidian University, Xi'an, Shaanxi 710071, China ; These authors contributed equally to this work.
Biomed Opt Express. 2013 Sep 23;4(10):2209-23. doi: 10.1364/BOE.4.002209. eCollection 2013.
Modeling light propagation in the whole body is essential and necessary for optical imaging. However, non-scattering, low-scattering and high absorption regions commonly exist in biological tissues, which lead to inaccuracy of the existing light transport models. In this paper, a novel hybrid light transport model that couples the simplified spherical harmonics approximation (SPN) with the radiosity theory (HSRM) was presented, to accurately describe light transport in turbid media with non-scattering, low-scattering and high absorption heterogeneities. In the model, the radiosity theory was used to characterize the light transport in non-scattering regions and the SPN was employed to handle the scattering problems, including subsets of low-scattering and high absorption. A Neumann source constructed by the light transport in the non-scattering region and formed at the interface between the non-scattering and scattering regions was superposed into the original light source, to couple the SPN with the radiosity theory. The accuracy and effectiveness of the HSRM was first verified with both regular and digital mouse model based simulations and a physical phantom based experiment. The feasibility and applicability of the HSRM was then investigated by a broad range of optical properties. Lastly, the influence of depth of the light source on the model was also discussed. Primary results showed that the proposed model provided high performance for light transport in turbid media with non-scattering, low-scattering and high absorption heterogeneities.
对全身光传播进行建模对于光学成像至关重要且必不可少。然而，生物组织中通常存在非散射、低散射和高吸收区域，这导致现有光传输模型不准确。本文提出了一种新型混合光传输模型，该模型将简化球谐近似（SPN）与辐射度理论（HSRM）相结合，以准确描述在具有非散射、低散射和高吸收不均匀性的混浊介质中的光传输。在该模型中，辐射度理论用于表征非散射区域中的光传输，而SPN用于处理散射问题，包括低散射和高吸收子集。由非散射区域中的光传输构建并在非散射区域与散射区域之间的界面处形成的诺伊曼源被叠加到原始光源中，以将SPN与辐射度理论耦合。首先通过基于常规和数字小鼠模型的模拟以及基于物理模型的实验验证了HSRM的准确性和有效性。然后通过广泛的光学特性研究了HSRM的可行性和适用性。最后，还讨论了光源深度对模型的影响。主要结果表明，所提出的模型在具有非散射、低散射和高吸收不均匀性的混浊介质中的光传输方面具有高性能。
