摘要
本研究提出一种基于π线的扇形束CT超短扫描优质重建算法,新算法仍采用经典的FBP重建算法框架,当且仅当满足通过感兴趣区域的任一直线均与扫描轨道相交时,就可以有效地进行该区域的精确重建。新重建公式中回避了投影数据的求导运算,将加权Hilbert滤波转化为Hilbert滤波与Ramp滤波的组合形式。由于实际重建过程中要对离散数据进行处理,新算法中导数的回避将增加数值计算稳定性,提高重建图像质量。为验证新算法理论分析的有效性,通过与经典的超短扫描重建算法作对比实验,结果印证了新算法可完成超短扫描优质重建,在数值计算稳定性与重建图像质量提高两方面均有尚佳表现。
An improved super-short-scan reconstruction algorithm was proposed for fan-beam computed tomography based on π-line. The new algorithm was also based on a FBP algorithm, which could achieve exact region of interest （ROI） reconstruction if and only if all lines passing through the region of interest （ROI） intersect the source trajectory. The new reconstruction formula successfully avoided the direct derivatives with respect to projection data and was expressed as the combination of Hilbert filter and Ramp filter instead of only Hilbert filter, which increased the numerical stability and achieved good image quality improvement in the real discrete data reconstruction. A preliminary computer-simulation study was performed well for validating and demonstrating this new super-short-scan reconstruction algorithm in beth numerical stability and reconstructed images quality improvement through comparing with other classic super-short-scan reconstruction algorithms.
出处
《中国生物医学工程学报》
CAS
CSCD
北大核心
2008年第3期347-352,共6页
Chinese Journal of Biomedical Engineering
基金
国家重点基础研究(973)计划项目(2003CB716101)
