基于分割增广拉格朗日收缩的X射线发光断层成像

X-Ray Luminescence Computed Tomography Based on Split Augmented Lagrangian Shrinkage Algorithm

利用纳米发光材料的X射线发光断层成像(XLCT)作为一种新型的成像模态,能够同时进行功能成像以及分子成像。在XLCT中,光子在组织中的散射效应使得纳米发光目标的重建具有不适定性,因此如何快速、精确地重建目标成为一个难题。针对此问题,选择扩散近似模型描述组织中的光子传输过程,采用基于L1正则化的分割增广拉格朗日收缩方法进行重建。在数值实验和物理实验中,将其与初始增广拉格朗日方法对比,验证其可行性。实验结果表明,该算法得到的重建结果无论在质量方面还是在收敛速度方面都具有一定优势。

Using the nanophosphors, X-ray luminescence computed tomography （XLCT） is proposed as a new molecular imaging modality that provides functional and molecular imaging capability. The reconstruction for the nanophosphors sample distribution is an ill-posed problem due to the strong scattering of photons in biological tissues. So accurate and stable reconstruction of nanophosphors distribution remains a challenging problem. In order to solve the problem, the diffusion approximation model is chosen to describe the photon transfer process, and the split augmented Lagrangian shrinkage algorithm based on L1 regularization is used for reconstruction. In the numerical simulations and physical experiments, the new method exhibits better performance in imaging quality and convergence rate compared with primal augmented Lagrangian method.