University of Alberta, Department of Electrical and Computer Engineering, Edmonton, Alberta, Canada.
J Biomed Opt. 2013 Jun;18(6):067005. doi: 10.1117/1.JBO.18.6.067005.
Oblique incidence reflectometry (OIR) is an established technique for the estimation of tissue optical properties. However, a sensing footprint of a few transport mean-free paths is often needed when diffusion-regime-based algorithms are used. Smaller-footprint probes require improved light-propagation models and inversion schemes for diffuse reflectance close to the point of entry but might enable micro-endoscopic form factors for clinical assessments of cancers and precancers. The phase-function corrected diffusion theory presented by Vitkin et al. [Nat. Commun. 2, 587 (2011)] to the case of pencil beams obliquely incident on a semi-infinite turbid medium is extended. The model requires minimal computational resources and offers improved accuracy over more traditional diffusion-theory approximations models when validated against Monte Carlo simulations. The computationally efficient nature of the models lends itself to rapid fitting procedures for inverse problems. The analytical model is used in a nonlinear fitting algorithm to demonstrate the recovery of optical properties using a measurement footprint that is significantly smaller than needed in previous diffusion-regime OIR methods.
斜入射反射率（OIR）是一种用于估计组织光学特性的成熟技术。然而，当使用基于扩散理论的算法时，通常需要几个输运平均自由程的传感足迹。较小足迹的探头需要改进的光传播模型和用于接近进入点的漫反射的反演方案，但可能能够实现用于癌症和癌前病变的临床评估的微内窥镜形态因子。Vitkin 等人[Nat. Commun. 2, 587 (2011)]针对倾斜铅笔束入射到半无限混浊介质的情况，对修正相位函数的扩散理论进行了扩展。该模型需要最少的计算资源，并且在与蒙特卡罗模拟进行验证时，与更传统的扩散理论近似模型相比，提供了更高的准确性。模型的高效计算性质使其适用于逆问题的快速拟合过程。该分析模型用于非线性拟合算法中，以证明使用比以前的扩散理论 OIR 方法所需的测量足迹小得多的足迹来恢复光学性质。
