CT图像重建中的一种新型滤波器  

A novel filter for CT image reconstruction

作　　者：杨坪坪 冯汉升 许继伟 宋云涛[1,2,3] YANG Pingping;FENG Hansheng;XU Jiwei;SONG Yuntao(University of Science and Technology of China,Hefei 230026,China;Institute of Plasma Physics,Chinese Academy of Sciences,Hefei 230031,China;Hefei CAS Ion Medical and Technical Devices Co.Ltd,Hefei 230088,China)

机构地区：[1]中国科学技术大学,安徽合肥230026 [2]中国科学院等离子体物理研究所,安徽合肥230031 [3]中科离子医学技术装备有限公司,安徽合肥230088

出　　处：《中国医学物理学杂志》2021年第7期814-819,共6页Chinese Journal of Medical Physics

摘　　要：滤波反投影图像重建算法中滤波器设计是其中至关重要的一环。针对现有一次指数滤波器空域波形存在明显振荡、频域曲线截止频率附近没有明显压低的问题,引入高斯滤波器减小Gibbs效应,并设计一种用于CT重建领域的新型滤波器,即改进高斯滤波器。通过仿真实验对比说明滤波器中加权因子选择对图像质量的影响,另与RL滤波器、SL滤波器、一次指数滤波器、高斯滤波器实验对比验证了该滤波器拥有良好的抗噪性能,有效减小重建图像灰度波动以及明显提高重建图像质量。Filter design is an important part in the filtered back projection image reconstruction algorithm.In view of the problem that the existing first-order exponential filter has obvious oscillations in the space domain waveform and no significant pressure drop near the cut-off frequency of the frequency-domain curve,a Gaussian filter is introduced to reduce Gibbs effect,and a novel filter(improved Gaussian filter)is designed for CT image reconstruction.The comparison of simulation experiments reveals the effect of the selection of weighting factors in the filter on the image quality.In addition,the comparison among RL filter,SL filter,first-order exponential filter and Gaussian filter verify that the proposed filter has a good anti-noise performance,and that it can effectively reduce the grayscale fluctuation of the reconstructed image and significantly improve the quality of the reconstructed image.

关 键 词：计算机断层成像技术 图像重建 一次指数滤波器 高斯滤波器 仿真实验 

分 类 号：R318[医药卫生—生物医学工程] TP301.6[医药卫生—基础医学]