REVEALING THE MATERIAL DIMENSION: MULTI-ABSORPTION PLATE TECHNOLOGY APPLIED TO SINGLE-EXPOSURE RADIOGRAPHY

摘要

We have developed a technology which allows energy-dependent materials information to be extracted from a single radiography exposure collected at a single X-ray kVp setting. The degeneracy between material and thickness information can therefore be overcome, allowing images to be generated showing materials contrast, as well as providing conventional absorption contrast images. There is no pre-requisite for materials to show absorption contrast in order to show materials contrast. Obtaining materials contrast is achieved by placing a Multi-Absorption Plate (MAP) in front of the detector [1]. The MAP is a 3D, periodic structure providing different degrees of absorption of the X-ray beam locally. This affects the spectrum of X-rays hitting any given pixel of the detector and allows energy-dependent information to be recovered, and thus material information to be obtained. For high-volume inspection, increased sensitivity to small structural and/or materials deviations from "normal" product can be obtained by building a mathematical model of "normal" product and allowed variability, based on the materials information obtained using the MAP. Test cases are presented, showing applications of this technology in different areas, including electronics / industrial / security inspection, medical applications and contaminant detection in food products.