摘要
双能CT技术可以重建物质的原子序数和电子密度信息,是一种有效的物质辨别技术。进行X射线能谱估计是双能重建的前提,能谱估计的准确性直接影响双能重建结果。但是,目前还没有学者对能谱估计的误差如何影响双能图像质量进行系统的研究。本文从双效应分解双能重建出发,量化分析能谱估计误差对双能重建结果的影响并给出误差传递的理论计算方法,论证影响双能图像准确重建的关键因素,同时由此定义适用于双能成像分析的能谱误差和针对双能成像的等效能谱概念。初步实验结果验证了这些理论的有效性。
Dual-energy CT can be used for computing atomic number and electron density. As a result, we can discriminate unknown materials. Spectrum estimation is the fn＇st step in dual-energy CT. Its accuracy directly affects dual-energy CT results. However, no systematic studies concerning how spectrum estimation accuracycontributing to reconstruction results have been worked out up to now. This work employs photoelectric-Compton decomposition dual-energy CT reconstruction method. We quantitatively analyze the propagation process from spectrum estimation error to dual-energy CT results and give theoretical calculation method. We propose one way to define spectrum error for dual-energy CT and give the concept of equivalent spectrum. Simulations are shown to support our work.
出处
《CT理论与应用研究（中英文）》
2013年第4期571-578,共8页
Computerized Tomography Theory and Applications
基金
国家自然科学基金青年科学基金(11305073)
关键词
双能CT
物质辨别
能谱估计
误差分析
dual-energy CT
material discrimination
spectrum estimation
error analysis
