Research on the background correction method in x-ray phase contrast imaging with Talbot-Lau interferometer

TL;DR

This paper introduces a novel phase unwrapping method for background correction in x-ray phase contrast imaging with Talbot-Lau interferometers, enhancing measurement flexibility and accuracy.

Contribution

A new phase unwrapping solution that improves background correction by cyclically shifting raw images, allowing flexible phase measurement ranges.

Findings

Successfully subtracts system background without error

Enables flexible phase measurement range adjustment

Demonstrates effectiveness through experiments and analysis

Abstract

X-ray Talbot-Lau interferometer has been used widely to conduct phase contrast imaging with a conventional low-brilliance x-ray source. Typically, in this technique, background correction has to be performed in order to obtain the pure signal of the sample under inspection. In this study, we reported on a research on the background correction strategies within this technique, especially we introduced a new phase unwrapping solution for one conventional background correction method, the key point of this new solution is changing the initial phase of each pixel by a cyclic shift operation on the raw images collected in phase stepping scan. Experimental result and numerical analysis showed that the new phase unwrapping algorithm could successfully subtract contribution of the system's background without error. Moreover, a potential advantage of this phase unwrapping strategy is that its effective phase measuring range could be tuned flexibly in some degree for example to be (-pi+3, pi+3], thus it would find usage in certain case because measuring range of the currently widely used background correction method is fixed to be (-pi, pi].