University of Electro-Communications, Department of Mechanical Engineering and Intelligent Systems, Chofu, Tokyo, Japan.
J Biomed Opt. 2011 Nov;16(11):116022. doi: 10.1117/1.3653236.
Tomographic images of the optical properties can be reconstructed using inversion algorithms for diffuse optical tomography (DOT); however, changes in the optode coupling that occurs while obtaining an object's measurements may often lead to the presence of artifacts in the reconstructed images. To reduce the number of artifacts induced by optode coupling, previous studies have introduced (unknown) coupling coefficients in reconstruction algorithms, which were found to be effective for continuous wave- and frequency-domain DOT. This study aims to investigate the effects of optode calibration on the reconstructed images of time-domain DOT. Here, coupling coefficients are incorporated into the time-domain DOT algorithm based on a modified generalized pulse spectrum technique. The images of the absorption coefficient are reconstructed in various numerical simulations, phantom experiments, and in vivo experiments of time-domain DOT. As a result, the artifacts resulting from changes in optode coupling are reduced in the reconstructed images of the absorption coefficient, thereby demonstrating that introduction of coupling coefficients is effective in time-domain DOT. Moreover, numerical simulations, phantom experiments, and in vivo studies have validated this algorithm.
可以使用漫射光学断层扫描 (DOT) 的反演算法重建光学特性的层析图像; 然而，在获取物体测量时发生的光探头耦合变化通常会导致重建图像中出现伪影。为了减少由光探头耦合引起的伪影数量，先前的研究在重建算法中引入了（未知）耦合系数，这对于连续波和频域 DOT 被证明是有效的。本研究旨在研究光探头校准对时域 DOT 重建图像的影响。在这里，基于改进的广义脉冲谱技术，将耦合系数纳入时域 DOT 算法中。在各种数值模拟、体模实验和体内时域 DOT 实验中重建吸收系数图像。结果表明，吸收系数重建图像中的光探头耦合变化引起的伪影减少，从而表明在时域 DOT 中引入耦合系数是有效的。此外，数值模拟、体模实验和体内研究验证了该算法。
