一维高斯分布物体X射线同轴相衬成像参数优化

采用图像衬度、信噪比、分辨率和探测器抽样数作为X射线同轴相衬成像质量的综合评价标准,针对具有广泛应用意义的一维高斯型分布特征的物体,建立了最大化衬度优化和信噪比优化两种参数优化方法的优化流程.通过数值模拟的方式分别对亚微焦点源、激光驱动微焦点源及同步辐射源3种不同X射线源下的成像系统相关参数进行了优化.结果表明,两种优化方法各具优势,可根据不同的相衬成像需求选择相应的优化方法.同步辐射源同轴相衬成像系统采用信噪比优化方法较为合适,而亚微焦点源和激光驱动微焦点源则需根据不同的需求来选择优化方法,必要时还可对优化方法进行一定的修正.研究为不同条件下有着不同要求的优质X射线同轴相衬成像实验提供了保证.

Optimization of Parameters for 1-dimensional Gaussian Distribution Object in X-ray In-line Phase Contrast Imaging

Contrast, signal-to-noise ratio (SNR), resolution and sampling are used as an integrated evaluation standard for the imaging quality of the X-ray in-line phase contrast imaging system. Two kinds of parameters optimized flows for Maximum contrast and SNR optimized methods are erected for the object of one dimensional Gaussian distribution which is widely applied to many fields. The correlative parameters of the imaging systems under the radiation of sub-micrometer focus X-ray source, laser-based micrometer focus X-ray source and synchrotron radiation X-ray source are optimized by the means of numerical simulation. The outcome shows that each optimized method has its advantages and disadvantages. The optimized method can be chosen by different requirements of the in-line phase contrast imaging. The SNR optimized method is available to the synchrotron radiation X-ray source, while the optimized methods of the sub-micrometer focus X-ray source and laser-based micrometer focus X-ray source should be chosen according to different requirements and may be corrected if necessary. The research can provide sustain for high quality X-ray in-line phase contrast imaging of different conditions and requirements.