基于Mojette频域最小冗余覆盖的有限角度计算机层析成像重建

Limited-Angle Computed Tomography Reconstruction Based on Mojette Minimal Redundancy Coverage in Frequency Domain

基于Mojette投影变换的空域与频域性质,提出频域最小冗余覆盖的有限角度计算机断层成像(CT)重建算法。其中频域最小冗余覆盖即空域投影采样最少,也就是重建图像的投影数目最少、效率最高。通过研究发现了Mojette投影数据在其频域上的等效关系,将投影压缩在有限角度范围内,实现了有限角度CT图像重建。实验结果表明利用所提方法可得到较好的重建结果。

Based on the properties of Mojette projection transform in spatial and frequency domains, we propose a limited-angle computed tomography(CT)reconstruction algorithm with minimum redundancy coverage in the frequency domain. The minimum redundant coverage corresponds to the minimum spatial projection sampling(i.e., the reconstructed image has minimum number of projections with maximum efficiency). The equivalent relationship of the Mojette projection data in its frequency domain is determined. The limited-angle CT image reconstruction can be achieved by compressing the projections into a limited angular range. Experimental results show that high-quality reconstructed images can be obtained by using the proposed algorithm.