A modified diffusion synthetic acceleration method is proposed to speed up the convergence process of TD-RTE calculation by employing the finite element method, combined with OpenMP parallel technology to further enhance the computational efficiency. In addition, the sequential quadratic programming algorithm is applied with Gaussian Markov random field (GGMRF) regularization to reconstruct the absorption and scattering parameter fields simultaneously. The accuracy and efficiency of the proposed model are investigated. It was observed that the modified DSA model is more efficient with the increase of the optical thickness, where the acceleration ratio is improved to 6 for the optical thicker media. In addition, similar acceleration effect was witnessed for both scattering dominated and non-scattering dominated media. Furthermore, by employing the modified DSA model into the reconstruction, it is interesting to remark that not only the reconstruction time is significantly reduced with the acceleration ratio of 8–11, but also the reconstructed image is further improved. All the results indicate that the developed scheme is efficient and robust based on TD-RTE, showing great potential in optical imaging.

提出一种改进的扩散合成加速方法，采用有限元方法加快TD-RTE计算的收敛过程，结合OpenMP并行技术，进一步提高计算效率。此外，序列二次规划算法与高斯马尔可夫随机场（GGMRF）正则化一起应用，以同时重建吸收和散射参数场。研究了所提出模型的准确性和效率。观察到修改后的 DSA 模型随着光学厚度的增加而更加有效，其中对于光学较厚的介质，加速比提高到 6。此外，对于散射主导和非散射主导的介质，都见证了类似的加速效果。此外，通过将修改后的 DSA 模型用于重建，有趣的是，不仅重建时间显着减少，加速比为 8-11，而且重建图像得到进一步改善。所有结果表明，所开发的基于 TD-RTE 的方案高效且鲁棒，在光学成像方面显示出巨大的潜力。