为了实现快速、准确、鲁棒的荧光分子断层成像(FMT)重建, 有限投影FMT和可行域选取策略得到了越来越多的关注。为了解决现有的可行域选取方法中存在的参数设置困难以及多目标选取不准确的问题, 从而提高有限投影FMT的重建质量, 提出了应用迭代自组织数据分析技术算法(ISODATA)的FMT可行域选取方法。首先采用ISODATA对初级重建结果聚类分区, 然后在各分离的区域上分别选取可行域。为了验证提出的方法在应用中的可行性和有效性, 设计了三目标荧光团重建的对比实验。实验结果显示,使用2个投影数据时, 只有使用本文提出的方法可以准确地重建出三个荧光源的位置; 使用4个投影数据时, 重建的平均位置误差为0.18 mm, 荧光产额相对误差小于50%, 而此时使用阈值法不能重建, 使用区域收缩法的荧光产额相对误差为61.2%。即使在测量数据较少时, 提出的方法也可以准确高效地选取可行域, 提高有限投影FMT重建的精确度和鲁棒性。

In order to achieve a fast, accurate, and robust reconstruction of fluorescence molecular tomography (FMT), limited-projection FMT and permissible region selection methods have been drawing more and more attention. Aiming to solve the problems of existing permissible region selection methods including the difficulty of parameter setting and the inaccuracy of multi-objective selection, so as to improve reconstruction quality of the limited-projection FMT, a method through which permissible regions were selected by applying an iterative self-organizing data analysis technique algorithm (ISODATA) was proposed. Firstly, ISODATA was used to cluster the primary reconstruction results, and then permissible regions were selected at every separated cluster. A contrast experiment of reconstructing three target fluorophores was designed to verify the feasibility and effectiveness in the application. The experimental results indicate that positions of all the three fluorophores can be reconstructed accurately with two projections only by using the proposed selection method. With four projections, the average localization error of reconstruction results is 0.18 mm and the relative error of the fluorescence yield is less than 50 %. Meanwhile, the threshold method fails to reconstruct and the relative error of the fluorescence yield using the region-shrinking method is 61.2 %. The proposed method is able to select permissible regions accurately and efficiently even with little measurement data. Consequently, the accuracy and robustness of limited-projection FMT reconstruction are improved.