台阶模糊边的X射线同轴相衬成像参数优化

Parameter Optimization for Step Blurred Edge Distribution Feature in X-ray In-line Phase Contrast Imaging

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台阶模糊边分布特征的物体,提出了参数优化方法并建立了优化流程。通过数值模拟的方式分别对具有广泛代表性的亚微米焦点源、激光驱动微米焦点源及同步辐射源3种X射线源下成像系统的相关参数进行了优化。结果表明,基于优化方法的优化流程很好地完成了3种X射线源的同轴相衬成像参数优化。可见,这种优化方法具有广泛的应用意义,在根据具体情况对方法进行简单修正的基础上,可以完成任意X射线源下对具有台阶模糊边分布特征物体的同轴相衬成像优化工作。

Contrast, signal-to-noise ratio, resolution and sampling are used as an integrated evaluation standard for the imaging quality of the X-ray in-line phase contrast imaging system. The optimization flow of parameters for the proposed optimized method is erected for the object which has the feature of one dimensional step blurred edge distribution widely applied in many fields. The correlative parameters of the imaging systems under the radiation of sub-micrometer sized focus X-ray source, laser-based micrometer sized focus X-ray source and synchrotron radiation X-ray source are optimized by the means of numerical simulation. The outcome shows that the parameter optimization is completed commendably by the optimized flow. It is obvious that the method can be applied to the optimization of each X-ray source based on simple correction if necessary.