Visibility of Polychromatic Grating-Based X-Ray Imaging Systems Based on Wave-Optical Theories and Frequency Domain Analysis

Xiaohua Zhu,Chengpeng Wu,Li Zhang,Xi Zhang,Hewei Gao

doi:10.3389/fphy.2021.630337

Xiaohua Zhu, Chengpeng Wu + Show 3 more

Open Access

https://doi.org/10.3389/fphy.2021.630337

Copy DOI

Abstract

Grating-based X-ray phase-contrast imaging and tomography, applicable with traditional polychromatic X-ray tubes, have shown great potential for future applications of imaging with multimodal information indicating materials and microstructures simultaneously. The parameters and performance of the grating system could be simulated by a wave-optical simulation framework and proved feasible for the design and optimization of both coherent and incoherent gratings systems. However, the simulation involves real-space point-wise calculation of the Fourier transformation, and the direct expression of the relationship of the parameters was absent. In this work, we analyzed the Fourier domain characteristics of the simulated system and the presented visibility of the system of different energies in an analytical form. The derived direct expression which omitted the simulation process was validated with results of both simulation and real experiments and may help future designs, optimizations and studies of the energy-resolved characteristics of the system.

Highlights

Differential phase-contrast and dark-field contrast images of grating-based X-ray systems have proven the capability to produce much better contrast-to-noise ratios (CNRs) and to reveal more microstructure details [1,2,3,4], compared with the attenuation contrast which conventional X-ray imaging solely relied on
Wave-optical simulations of the Talbot-Lau interferometer have been developed by several groups [4, 10,11,12], and the application has been expanded to non-interferometric systems [13]
The detector energy response model is based on a theoretic model of a cesium iodide (CsI) flat-panel detector

Summary

Introduction

Differential phase-contrast and dark-field contrast images of grating-based X-ray systems have proven the capability to produce much better contrast-to-noise ratios (CNRs) and to reveal more microstructure details [1,2,3,4], compared with the attenuation contrast which conventional X-ray imaging solely relied on. The performance and characteristics of the system, especially with wide X-ray spectrum, are complicated and unpredictable, since parameters of the system as the grating design and the processing aspects, the system geometry, the detector response, and so forth all affect the nature of the X-ray stripes of different wavelength. A proven practicable approach of the system design and optimization is Visibility of Grating-Based X-Ray Systems performances and X-ray energy, and predicts the effect of X-ray spectrum and energy response, circumventing the simulation calculations (together with implementation details). The analytical model may help support further study, design, and optimization of grating-based X-ray imaging systems

Methods

Results

Conclusion