X-ray fan beam coded aperture transmission and diffraction imaging for fast material analysis

Stefan Stryker,Joel A Greenberg,Anuj J Kapadia,Shannon J Mccall

doi:10.1038/s41598-021-90163-0

Abstract

X-ray transmission imaging has been used in a variety of applications for high-resolution measurements based on shape and density. Similarly, X-ray diffraction (XRD) imaging has been used widely for molecular structure-based identification of materials. Combining these X-ray methods has the potential to provide high-resolution material identification, exceeding the capabilities of either modality alone. However, XRD imaging methods have been limited in application by their long measurement times and poor spatial resolution, which has generally precluded combined, rapid measurements of X-ray transmission and diffraction. In this work, we present a novel X-ray fan beam coded aperture transmission and diffraction imaging system, developed using commercially available components, for rapid and accurate non-destructive imaging of industrial and biomedical specimens. The imaging system uses a 160 kV Bremsstrahlung X-ray source while achieving a spatial resolution of ≈ 1 × 1 mm2 and a spectral accuracy of > 95% with only 15 s exposures per 150 mm fan beam slice. Applications of this technology are reported in geological imaging, pharmaceutical inspection, and medical diagnosis. The performance of the imaging system indicates improved material differentiation relative to transmission imaging alone at scan times suitable for a variety of industrial and biomedical applications.

Highlights

X-ray transmission imaging has been used in a variety of applications for high-resolution measurements based on shape and density
While non-imaging-based X-ray diffraction (XRD) is utilized widely in applications such as extra-terrestrial sample analysis[5], drug inspection[6,7,8], and material science[9,10], challenges arising from implementing measurements at relevant spatial resolutions and scan times prevent XRD from being widely used in imaging applications
The X-ray fan beam coded aperture imaging system combines high-resolution transmission imaging with coded aperture X-ray diffraction using predominantly off-the shelf components in a compact, user-friendly design that is appropriate for industrial, laboratory, and clinical applications

Summary

Introduction

X-ray transmission imaging has been used in a variety of applications for high-resolution measurements based on shape and density. Commercial diffractometers, the most widely used XRD architecture, utilize X-ray pencil beam geometries operating at low X-ray energies (e.g., the most commonly used copper anodes have a k-alpha energy of 8.05 keV), which allows for highly accurate localized identification of scatter on the surface of materials. While these systems can be used to generate planar XRD images of objects via raster scanning in two dimensions[11,12], this process requires significant sample preparation and is typically slow (often requiring hours to measure small objects[13,14]). As an initial exploration of applications, data were collected from geological, pharmaceutical, and medical specimens to evaluate and demonstrate the system’s utility in combined high-resolution imaging and material identification

Methods

Results

Conclusion