An improved multiple-image radiography method extracting refraction information in analyzer-based imaging

Analyzer-based imaging is one of X-ray phase-contrast imaging techniques, which generate improved contrast compared to the conventional absorption radiography. The refraction images of an investigated object can be yielded using a given number of raw images measured at different positions of analyzer crystal along its rocking curve. When applying the multiple-image radiography (MIR) method to retrieve the refraction-angles, the calculated values always underestimate the actual ones (particularly for high refraction angles). An improved method of MIR is proposed and developed in this paper. The computer simulation experiment is performed to draw comparison of the proposed method and the original MIR method. The findings suggest that under the same sampling condition, the proposed method can produce more accurate refraction images. Besides, the difference of computation time between them can be negligible. The proposed method may be useful in practical application of extracting refraction images as a valid alternative to the original MIR method.