相干性与参数对类同轴X射线相衬成像影响的研究

Research on the Influence of Coherence and Parameters by In-line X-ray Phased Imaging

微焦点源类同轴X射线相衬成像利用相位信息进行成像,与传统的基于吸收衰减的X射线成像不同,不仅可以对骨骼、肌肉等大密度物质进行成像,还可对低密度、弱吸收的样品进行成像。首先对类同轴X射线相衬成像的原理进行分析,得到了理想条件下的成像公式;然后在此基础上,分析了时间相干性和空间相干性对相衬成像的影响;考虑空间相干强度之后,得到了临床上类同轴X射线相衬成像公式,并对其参数进行Matlab仿真分析,得到其变化规律,为接下来的实验提供思路与方法,从而获得满意的图像。

Micro-focus source coaxial X-ray phase contrast imaging uses phase information for imaging.Unlike traditional absorption-attenuation-based X-ray imaging,it can not only image large-density materials such as bones and muscles,but also low-density,Weakly absorbed samples were imaged.Firstly,the principle of coaxial X-ray phase contrast imaging is analyzed,and the imaging formula under ideal conditions is obtained.Then,the influence of temporal coherence and spatial coherence on phase contrast imaging is analyzed.After considering the spatial coherence intensity,a clinically-like coaxial X-ray phase contrast imaging formula is obtained,and the parameters are analyzed by Matlab to obtain the change rule,and the ideas and methods for the next experiment are provided to obtain a satisfactory image.