On the quantification of sample microstructure using single-exposure x-ray dark-field imaging via a single-grid setup

• Published in: Scientific reports Vol. 13; no. 1; p. 11001
• Main Authors: How, Ying Ying, Paganin, David M., Morgan, Kaye S.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 07-07-2023; Nature Publishing Group; Nature Portfolio
• Subjects: 639/624/1107/510; 639/624/400/1106; 639/766/400/1106; 639/766/930/2735; Experimental data; Humanities and Social Sciences; Microspheres; Microstructure; Models, Theoretical; multidisciplinary; Polystyrene; Science; Science (multidisciplinary); Spatial discrimination; X-ray scattering; X-Rays
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-023-37334-3

The size of the smallest detectable sample feature in an x-ray imaging system is usually restricted by the spatial resolution of the system. This limitation can now be overcome using the diffusive dark-field signal, which is generated by unresolved phase effects or the ultra-small-angle x-ray scattering from unresolved sample microstructures. A quantitative measure of this dark-field signal can be useful in revealing the microstructure size or material for medical diagnosis, security screening and materials science. Recently, we derived a new method to quantify the diffusive dark-field signal in terms of a scattering angle using a single-exposure grid-based approach. In this manuscript, we look at the problem of quantifying the sample microstructure size from this single-exposure dark-field signal. We do this by quantifying the diffusive dark-field signal produced by 5 different sizes of polystyrene microspheres, ranging from 1.0 to 10.8 µm, to investigate how the strength of the extracted dark-field signal changes with the sample microstructure size,
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. We also explore the feasibility of performing single-exposure dark-field imaging with a simple equation for the optimal propagation distance, given microstructure with a specific size and thickness, and show consistency between this model and experimental data. Our theoretical model predicts that the dark-field scattering angle is inversely proportional to
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, which is also consistent with our experimental data.