光源最优可行区自动选取算法在生物发光断层成像中的应用

An Optimal Automatic Selection Algorithm of Permissible Source Region Applied in Bioluminescence Tomography

目的提出一种最优可行区的自动选取方法,以降低生物发光断层成像光源重建过程中的病态性和欠定性问题。方法根据光子传播模型将CCD获得的二维图像映射为体表光辐照度;利用有限元法求解光源与体内光强分布的关系矩阵;利用该文提出的最佳可行区自动选取方法确定光源可行区,并用吉洪诺夫正则化方法重建光源。结果最优可行区中心点与真实光源中心点距离为1.26 mm,重建光源中心点误差为0.45 mm,体积误差为9.13 mm3。结论该文提出的光源最佳可行区选取策略可有效地将可行区定位到真实光源附近,减少因主观定位可行区带来的重建误差,为获得高精度的光源重建结果提供保障。

Objective An optimal automatic selection method of permissible source region is proposed to reduce the ill-conditioned and ill-posed problems in the reconstruction of the light source in bioluminescence tomography. Methods The 2D images captured by CCD are mapped into surface light irradiance distribution based on the light propagating model. The relation matrix between the source and light distribution is obtained by finite element method. Permissive source region is determined by using the automatic selection method proposed in this paper, and then -I-ikhonov regularization is applied to reconstruct the light source. Results The center point distance between the optimal permissible source region and true source is 1.26 mm, and the center point error of the reconstructed light source and true source is 0.47 mm, the volume error is 9.13 mm3. Conclusion The optimal permissive source region selection strategy is effective to locate the permissive source region close to the true source, and reduces the reconstructed error due to subjective orientation of permissible source region. This proposed method is the basis of high precision source reconstruction in bioluminescence tomography.