Das Tapan, Dileep B P V, Dutta Pranab K
Appl Opt. 2018 Mar 10;57(8):1838-1848. doi: 10.1364/AO.57.001838.
Near-infrared imaging (NIRI) is a sub-surface imaging that makes a trade-off in recovery accuracy with depth of penetration. On the other hand, diffuse optical tomography (DOT) images tissue up to several centimeters. However, DOT reconstruction has a stability issue due to the inverse problem. This paper proposes a generalized continuous-wave technique to image objects of dimensions 4-6 cm comparable to DOT. A nonlinear Rosenbrock's banana function is fitted to the approximate photon path, and the fit parameter thus obtained gives the penetration depth of each channel. The calculated values of absorption change are back-projected along these curved paths for reconstruction without solving the inverse problem. This function serves as an operator for image reconstruction. Here numerical simulations, experimental validation on wax phantom with inclusions, finger joint, and degraded apple have been performed to show potential of the proposed method in imaging. Thus this computationally efficient, reliable, and simple method is suitable for practical and real-time NIRI applications.
近红外成像（NIRI）是一种表面下成像技术，它在恢复精度和穿透深度之间进行权衡。另一方面，扩散光学层析成像（DOT）可对几厘米厚的组织进行成像。然而，由于逆问题，DOT重建存在稳定性问题。本文提出一种广义连续波技术，用于对尺寸与DOT相当（4 - 6厘米）的物体进行成像。将非线性罗森布罗克香蕉函数拟合到近似光子路径上，由此获得的拟合参数给出每个通道的穿透深度。对于吸收变化的计算值，沿着这些弯曲路径进行反投影以进行重建，而无需解决逆问题。该函数用作图像重建的算子。本文进行了数值模拟，以及在含有内含物的蜡体模型、手指关节和变质苹果上的实验验证，以展示所提方法在成像方面的潜力。因此，这种计算效率高、可靠且简单的方法适用于实际的实时NIRI应用。
