X射线光谱信息是进行X射线曝光剂量控制、X射线成像质量评估、X射线双能量成像等必不可少的,为此本文提出一种基于模型的钨靶X射线球管光谱重建方法.该方法首先建立一个具有物理意义的7参数球管光谱模型,再通过测量的光谱衰减数据求解模型参数进而重建光谱.实验中,对若干球管电压分别选择不同厚度的铝板和铜板作为衰减器测量衰减数据,结合模型由衰减数据重建光谱.实验表明,该方法可利用较少的衰减数据重建包含特征辐射的球管光谱,算法简单易行.与原始光谱获得的衰减数据相比,重建光谱获得的衰减数据误差低于0.3%;与修正的手册光谱相比,重建光谱误差低于5%.
Knowledge of X-ray spectra is essential for X-ray dose control,X-ray image quality evaluation and dual-energy X-ray imaging etc.A model-based tungsten anode X-ray tube spectra reconstruction method is presented in this paper.A physical meaningful seven-parameter X-ray tube spectra model is firstly established.Then model parameters are estimated from attenuation data so that X-ray tube spectra can be reconstructed.In the experiment,a series of aluminum plates and copper plates with different thickness are selected as attenuator for a selected tube voltage.Model parameters are estimated from experimentally measured attenuation data to reconstruct X-ray tube spectra.Experiments show that the method is easy to apply and can reconstruct both bremsstrahlung and characteristic spectra with only a few attenuation data.The difference of attenuation data between initial spectra and reconstructed spectra is lower than 0.3%.The difference between modified handbook spectra and reconstructed spectra is lower than 5%.