中文摘要：

透射测量是层析γ成像扫描中发射测量的基础,合理的重建算法是透射图像重建的核心。结合TGS透射测量的特点,利用蒙特卡罗模拟构建了EM、Richardson、ART三种迭代算法模型,分析对比了三种算法的误差。同时开展了透射测量实验,实验数据表明ART算法重建值相对参考值的最大误差为29%,并且多个体素超过20%;而Richardson算法仅为15%,其中只有10个体素重建值大于10%,虽然相对ART算法有很大提升,但所得的偏差值还是很大;EM算法相比前两种算法有明显的优势,即使出现了几个相对误差值大于10%的体素,但都处于图像边缘,对整体重建影响非常小。

英文摘要：

Transmission measurement in tomography gamma scanning is the basis of emission measurement,and image reconstruction algorithm is the core problem of transmission measurement image reconstruction. Considering the characteristics of TGS transmission measurement,three iterative algorithms of EM,Richardson and ART are constructed by Monte Carlo simulation,the errors of three algorithms are analyzed and compared. The transmission measurement experiments were carried out respectively,the experiments data show that the maximal relative error between the reconstructed value and the reference value of the ART algorithm is 29%,and several voxels are more than 20%. However,the Richardson algorithm is 15%,and the reconstruction error among 10 voxels is about10%,which is better than ART algorithm,but the error is still higher relatively. EM algorithm is better than the previous two algorithms,although there are several voxels＇ errors is more than 10%,but locating in the image＇s corner,which have almost no effect on the reconstruction effect.