基于改进平滑硬阈值约束的 CT 迭代重建算法

摘要

Image reconstruction for sparse view computed tomography is an effective way to reduce x-ray radia-tion.A modified SHT has been proposed for sparse-view CT image reconstruction.The improved SHT is much closer to L0 norm than SHT.The parameter in modified SHT is not affected by reconstructed image.Similar to ART-TV reconstruction strategy,our method in this study includes ART reconstruction followed by improved SHT minimization.Experimental results have demonstrated that new method can lead to images with better qual-ity,higher signal-to-noise ratio and lower mean absolute error.%稀疏角度投影数据重建CT图像，是一种有效的降低X射线辐射剂量的方式。提出一种改进的平滑硬阈值（ SHT）约束，使其更接近于L0范数，同时最优参数不受重建图像影响。该重建算法沿用ART－TV的重建策略，即对每次ART重建后的图像进行改进SHT的最小化约束。实验表明：新算法提高了重建图像质量，信噪比更高，平均绝对误差更小。