基于投影空间的CT射束硬化校正方法  

CT beam hardening correction method based on projection space

作　　者：张小可 杨昆[1] 陈锦涛 薛林雁[1] 李晓苇[2] ZHANG Xiaoke;YANG Kun;CHEN Jintao;XUE Linyan;LI Xiaowei(College of Quality and Technical Supervision,Hebei University,Baoding 071002,China;College of Physical Science&Technology,Hebei University,Baoding 071002,China)

机构地区：[1]河北大学质量技术监督学院,河北保定071002 [2]河北大学物理科学与技术学院,河北保定071002

出　　处：《河北大学学报（自然科学版）》2018年第6期648-655,共8页Journal of Hebei University(Natural Science Edition)

基　　金：国家自然科学基金资助项目(11104058);国家重点基础研究发展规划项目(2011CB707500);河北省自然科学基金资助项目(A2011201155);科技部重大科学仪器专项计划(2011YQ03011405);科技部重点研发计划(2016YFC0104203);河北省教育厅重点项目(ZD2015044)

摘　　要：针对医用X线CT成像系统的多色能谱X线在成像过程中出现的CT图像硬化伪影,会降低图像质量,干扰诊断等问题,需要对CT硬化伪影进行校正.本文对于单介质水和水骨混合物分别提出了一种基于投影空间优化的多项式拟合校正方法.首先,构建投影校正模型和理想投影模型;然后,将构建的投影校正模型与理想投影模型做对比,差异最小时确定校正系数;最后,把校正系数代入投影校正模型中再重建图像.经仿真实验结果表明,所提出的多项式拟合校正方法能够很好地去除CT硬化伪影,提高图像精度,对CT的精准定量分析具有重大意义.X ray spectrum of medical CT imaging system is polychromatic,which will cause CT image hardening artifacts,reduce image quality and interfere diagnosis.Therefore,the correction of the hardening artifacts of CT images is necessary.In this paper,a polynomial fitting correction method is proposed based on projection space optimization for single medium water and water bone mixture.Firstly,the projection correction model and the ideal projection model are constructed.Then,the projection correction model is compared with the ideal projection model to determine the correction coefficient when the difference is minimum.Finally,the correction coefficient is substituted into the projection correction model,and the corrected image can be reconstructed.The simulation results show that the proposed polynomial fitting correction method can remove CT hardening artifacts and improve the image accuracy,which is of great significance in the accurate quantitative analysis of CT.

关 键 词：计算机断层扫描(CT) 射束硬化校正 投影空间 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]