基于等角多段探测器的非均匀采样CT直接FBP重建算法研究

Research on FBP reconstruction algorithm for non-uniform sampling CT based on equiangular multi-segment detectors

本文提出了一种基于等角多段探测器的非均匀采样计算机断层成像(Computed Tomography,CT)系统,并针对该系统推导了直接滤波反投影重建算法,分析了算法在处理非均匀采样CT数据时的局限性,特别是算法中权重函数的非光滑性对重建图像的影响。本文的理论推导和仿真实验结果显示:尽管直接滤波反投影(Filtered Back Projection,FBP)重建算法可能导致环状伪影,但通过适当的系统设计,这些伪影的影响可以被控制在可接受的范围内,并能保持图像的分辨率,使得基于等角多段探测器的非均匀采样CT的FBP算法具有一定的实用价值。本文研究成果为新型CT系统的设计和优化提供了理论依据和实践指导。

This paper proposes a non-uniform sampling CT system based on equiangular multi-segment detectors,and derives a direct filtered back-projection(FBP)reconstruction algorithm for this systemIt analyzes the limitations of the algorithm when dealing with non-uniformly sampled CT data,especially the impact of the non-smoothness of the weight function in the algorithm on reconstructed imagesThe theoretical derivation and simulation results of this work show that,although the direct FBP algorithm may lead to ring artifacts,these artifacts can be controlled within an acceptable range through appropriate system design,which making the FBP algorithm based on equiangular multi-segment detectors for non-uniformly sampled CT practical and capable of maintaining image resolutionThe findings of this paper provide a theoretical basis and practical guidance for the design and optimization of new CT systems.