摘要
X线CT系统球管发射宽能谱X光子,使得重建图像中出现射束硬化伪影,如杯形和条纹伪影;成像对象体内还可能存在金属植入物,使得重建图像中出现金属伪影。多种图像伪影的同时出现,势必严重退化临床诊断精度,有必要深入研究加以抑制。本文利用数据一致性条件构造目标函数;利用非线性最小二乘和交替迭代优化算法求解最优尺度因子;最终得到可同时校正杯形、条纹和金属伪影的最优骨校正方法。计算机仿真实验结果表明,该方法的确能够自适应确定出最优尺度因子,从而同时校正多种图像伪影。
Tube of X-ray CT system emitting a polychromatic spectrum of photons leads to beam hardening artifacts such as cupping and streaks, while the metal implants in the imaged object results in metal artifacts in reconstructed images. The simultaneous emergence of various types of image artifacts certainly will degrade the diagnostic accuracy in clinics, and so should be deeply researched for suppressing them. In this paper, data consistency condition is exploited to construct an objective function. Nonlinear least square and alterative iteration algorithms are used to solve the optimal scaling factors. Finally, an optimal bone correction approach is acquired to simultaneously correct for cupping, streaks and metal artifacts. Experimental result acquired by a computer simulation demonstrates that the proposed approach can really adaptively determine the optimal scaling factors, and then correct for various types of image artifacts at the same time.
出处
《CT理论与应用研究（中英文）》
2018年第3期301-314,共14页
Computerized Tomography Theory and Applications
基金
西邮新星团队基金
西北工业大学现代设计与集成制造教育部重点实验室(KF201401)
东南大学计算机网络与信息集成教育部重点实验室(K93-9-2017-03)
陕西省教育厅(15JK1673)
陕西省科技厅(2016JM8034)
国家自然科学基金(61501310)
关键词
X线CT
射束硬化
一致性条件
X-ray CT
beam hardening
consistency condition
