摘要
为了提高双能CT基材料分解的精度,降低基材料图像的噪声,提出了基于MAP-EM算法的直接迭代基材料分解方法.结合MAP-EM算法,推导出基材料分解直接迭代求解公式,基于双能投影数据集直接重建基材料分解图像,并对该方法的性能进行了评价和分析.仿真结果表明,所提方法可显著降低分解误差和基材料图像噪声,提高对比噪声比.与基于FBP算法的图像域基材料分解方法相比,该方法可使基材料图像中各材料区域的噪声水平下降57.42%~63.64%,分解误差水平降低31.72%~62.14%,对比噪声比提高1.37%~223.17%.
To improve the accuracy of basis material decomposition and reduce the noise in the basis material images for dual-energy CT(computed tomography),a direct iterative basis material decomposition method based on the MAP-EM(maximum a posteriori expectation-maximization)algorithm was proposed.Combined with the MAP-EM algorithm,the direct iterative formulas for basis material decomposition were derived.The basis material decomposition images were directly reconstructed from the dual-energy projection data set.The performance of the method was evaluated and analyzed.The simulation results show that the proposed method can significantly reduce the error of decomposition and the noise of basis material images,and improve the contrast-to-noise ratio.Compared with the image domain basis material decomposition method based on the FBP(filtered back projection)algorithm,the proposed method can reduce the noise of each material region in the basis material images by 57.42%to 63.64%.The decomposition error levels of each material region in the basis material images can be reduced by 31.72%to 62.14%.The contrast-to-noise ratios of each material region in the basis material images can be improved by 1.37%to 223.17%.
作者
周正东
章栩苓
辛润超
贾峻山
魏士松
毛玲
Zhou Zhengdong;Zhang Xuling;Xin Runchao;Jia Junshan;Wei Shisong;Mao Ling(State Key Laboratory of Mechanics and Control of Mechanical Structures,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;Department of Nuclear Science and Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China)
出处
《东南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2020年第5期935-941,共7页
Journal of Southeast University：Natural Science Edition
基金
国家自然科学基金资助项目(51575256)
江苏省重点研发计划(社会发展)重点资助项目(BE2017730)
重庆市产业类重点研发(重大主题专项项目)资助项目(cstc2017zdcy-zdzxX0007)
上海航天科技创新基金资助项目(SAST 2019-121)
江苏高校优势学科建设工程资助项目(PAPD).
关键词
双能CT
基材料分解
MAP-EM
直接迭代
图像重建
dual-energy CT(computed tomography)
basis material decomposition
MAP-EM(maximum a posteriori expectation-maximization)
direct iterative
image reconstruction
