光子计数X射线CT能量成像精度影响因素分析  

Analysis of Accuracy Related Factors in Photon Counting X-ray CT Energy Imaging

作　　者：曹家晟 李保磊 CAO Jiasheng;LI Baolei(Beijing Hangxing Machine Manufacturing Co.,Ltd.,Beijing 100013,China)

机构地区：[1]北京航星机器制造有限公司,北京100013

出　　处：《CT理论与应用研究(中英文)》2025年第2期255-262,共8页Computerized Tomography Theory and Applications

摘　　要：以光子计数探测器为核心的多能谱成像,成为X射线成像领域人们研究的焦点。本文利用Geant 4仿真软件生成射线源能谱,通过设置不同的能量阈值和探测器能量分辨率,获取不同范围的高低能能谱,扫描物体得到高低能投影数据进行双能重建,比较各组别下的等效原子序数和电子密度标准差。实验结果表明,探测器能量分辨率越高、高低能能谱区分度越大,成像效果越好,而能量阈值对成像精度的影响最终是通过改变能谱重合度,进而对成像精度造成影响。同时,随着能谱重合度变小、能谱宽度变窄,噪声也会加大,因此需要平衡能谱重合度和噪声的关系,才能达到更好的成像效果。Multi-energy spectrum imaging with photon counting detectors has become the focus of X-ray imaging.In this study,the Geant4 simulation software was used to generate the energy spectrum of the ray source,obtaining high-low energy spectra of different ranges by setting different detector energy resolutions and changing the energy threshold.High-low energy projection data of scan objects were obtained for dual-energy reconstruction.The standard deviation of the effective atomic number and electron density under each group were compared.The results show that the higher the energy resolution and the greater the difference between high and low energy spectra,the better is the imaging quality.The energy threshold influenced the imaging accuracy when the spectrum overlap ratio was changed.When the spectrum overlap became smaller and the spectral width became narrower,noise increased,making it necessary to balance the relationship between spectrum overlap and noise to achieve better imaging results.

关 键 词：多能谱成像技术 光子计数探测器 X射线成像 计算机断层成像 双能重建 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]