J Opt Soc Am A Opt Image Sci Vis. 2022 May 1;39(5):841-846. doi: 10.1364/JOSAA.451319.
Wavelength-dependent absorption and scattering properties determine the fluorescence photon transport in biological tissues and image resolution of optical molecular tomography. Currently, these parameters are computed from optically measured data. For small animal imaging, estimation of optical parameters is a large-scale optimization problem, which is highly ill-posed. In this paper, we propose a new, to the best of our knowledge, approach to estimate optical parameters of biological tissues with photon-counting micro-computed tomography (micro-CT). From photon-counting x-ray data, multi-energy micro-CT images can be reconstructed to perform multi-organ segmentation and material decomposition in terms of tissue constituents. The concentration and characteristics of major tissue constituents can be utilized to calculate the optical absorption and scattering coefficients of the involved tissues. In our study, we perform numerical simulation, phantom experiments, and in vivo animal studies to calculate the optical parameters using our proposed approach. The results show that our approach can estimate optical parameters of tissues with a relative error of <10, accurately mapping the optical parameter distributions in a small animal.
波长依赖性吸收和散射特性决定了生物组织中的荧光光子传输和光学分子断层成像的分辨率。目前，这些参数是根据光学测量数据计算得出的。对于小动物成像，光学参数的估计是一个大规模的优化问题，具有高度不适定性。在本文中，我们提出了一种新的方法，据我们所知，利用光子计数微计算机断层扫描（micro-CT）来估计生物组织的光学参数。从光子计数 X 射线数据中，可以重建多能微 CT 图像，以根据组织成分进行多器官分割和材料分解。主要组织成分的浓度和特征可用于计算相关组织的光吸收和散射系数。在我们的研究中，我们进行了数值模拟、体模实验和体内动物研究，以使用我们提出的方法计算光学参数。结果表明，我们的方法可以以<10 的相对误差估计组织的光学参数，准确地在小动物体内绘制光学参数分布。
