Diemoz Paul C, Vittoria Fabio A, Olivo Alessandro
Opt Express. 2016 May 16;24(10):11250-65. doi: 10.1364/OE.24.011250.
Previous studies on edge illumination (EI) X-ray phase-contrast imaging (XPCi) have investigated the nature and amplitude of the signal provided by this technique. However, the response of the imaging system to different object spatial frequencies was never explicitly considered and studied. This is required in order to predict the performance of a given EI setup for different classes of objects. To this scope, in the present work we derive analytical expressions for the contrast transfer function of an EI imaging system, using the approximation of near-field regime, and study its dependence upon the main experimental parameters. We then exploit these results to compare the frequency response of an EI system with respect of that of a free-space propagation XPCi one. The results achieved in this work can be useful for predicting the signals obtainable for different types of objects and also as a basis for new retrieval methods.
先前关于边缘照明（EI）X射线相衬成像（XPCi）的研究探讨了该技术所提供信号的性质和幅度。然而，成像系统对不同物体空间频率的响应从未得到明确的考虑和研究。为了预测给定EI设置对不同类别物体的性能，这是必要的。为此，在本工作中，我们利用近场近似推导出EI成像系统对比度传递函数的解析表达式，并研究其对主要实验参数的依赖性。然后，我们利用这些结果比较EI系统与自由空间传播XPCi系统的频率响应。这项工作所取得的结果对于预测不同类型物体可获得的信号以及作为新的检索方法的基础可能是有用的。
