National University of Singapore, Division of Bioengineering, Faculty of Engineering, Singapore, Singapore.
J Biomed Opt. 2011 Mar;16(3):035001. doi: 10.1117/1.3549738.
Optimization of source and detector (SD) arrangements in a diffuse optical tomography system is helpful for improving measurements' sensitivity to localized changes in imaging domain and enhancing the capacity of noise resistance. We introduced a rigorous and computationally efficient methodology and adapt it into the diffuse optics field to realize the optimizations of SD arrangements. Our method is based on Cramer-Rao lower bound analysis, which combines the diffusion-forward model and a noise model together. This method can be used to investigate the performance of the SD arrangements through quantitative estimations of lower bounds of the standard variances of the reconstructed perturbation depths and values. More importantly, it provides direct estimations of parameters without solving the inverse problem. Simulations are conducted in the reflection geometry to validate the effectiveness of the method on selections of the optimized SD sets, with a fixed number of sources and detectors, from an SD group on a planar probe surface. The impacts of different noise levels and target perturbation depths are considered in the simulations. It is demonstrated that the SD sets selected by this method afford better reconstructed images. This methodology can be adapted to other probe surfaces and other imaging geometries.
在漫射光学层析成像系统中，优化光源和探测器（SD）的布置有助于提高测量对成像域中局部变化的灵敏度，并提高抗噪能力。我们引入了一种严格且计算效率高的方法，并将其应用于漫射光学领域，以实现 SD 布置的优化。我们的方法基于克拉美-罗下界分析，将扩散前向模型和噪声模型结合在一起。该方法可通过对重建扰动深度和值的标准方差下界的定量估计，来研究 SD 布置的性能。更重要的是，它无需求解逆问题即可提供参数的直接估计。在反射几何中进行了模拟，以验证该方法在从平面探针表面上的 SD 组中选择具有固定源和探测器数量的优化 SD 集方面的有效性。模拟中考虑了不同噪声水平和目标扰动深度的影响。结果表明，该方法选择的 SD 集可提供更好的重建图像。这种方法可以适应其他探头表面和其他成像几何形状。
