Virginia Polytechnic Institute and State University, School of Biomedical Engineering and Sciences, Biomedical Imaging Division, Blacksburg, Virginia 24061, USA.
J Biomed Opt. 2011 Jun;16(6):066014. doi: 10.1117/1.3592499.
The nanophosphors, or other similar materials, emit near-infrared (NIR) light upon x-ray excitation. They were designed as optical probes for in vivo visualization and analysis of molecular and cellular targets, pathways, and responses. Based on the previous work on x-ray fluorescence computed tomography (XFCT) and x-ray luminescence computed tomography (XLCT), here we propose a spectrally-resolving and scattering-compensated x-ray luminescence/fluorescence computed tomography (SXLCT or SXFCT) approach to quantify a spatial distribution of nanophosphors (other similar materials or chemical elements) within a biological object. In this paper, the x-ray scattering is taken into account in the reconstruction algorithm. The NIR scattering is described in the diffusion approximation model. Then, x-ray excitations are applied with different spectra, and NIR signals are measured in a spectrally resolving fashion. Finally, a linear relationship is established between the nanophosphor distribution and measured NIR data using the finite element method and inverted using the compressive sensing technique. The numerical simulation results demonstrate the feasibility and merits of the proposed approach.
纳米荧光粉或其他类似材料在 X 射线激发下发射近红外（NIR）光。它们被设计为光学探针，用于对分子和细胞靶标、途径和反应进行体内可视化和分析。基于之前关于 X 射线荧光计算机断层扫描（XFCT）和 X 射线发光计算机断层扫描（XLCT）的工作，我们在这里提出了一种光谱分辨和散射补偿的 X 射线发光/荧光计算机断层扫描（SXLCT 或 SXFCT）方法，以定量生物体内纳米荧光粉（其他类似材料或化学元素）的空间分布。在本文中，重建算法中考虑了 X 射线散射。NIR 散射在扩散近似模型中进行描述。然后，以不同的光谱施加 X 射线激发，并以光谱分辨的方式测量 NIR 信号。最后，使用有限元方法建立纳米荧光粉分布与测量的 NIR 数据之间的线性关系，并使用压缩感知技术进行反演。数值模拟结果证明了所提出方法的可行性和优点。
