Line Integral Retrieval and Reconstruction for X-Ray Fan-Beam Differential Phase Contrast CT

Abstract

A reconstruction technique for X-ray fan-beam differential phase-contrast computed tomography (DPC-CT) was reported in this paper. It consists of two steps which are line integral retrieval from the recorded DPC-CT projections and image reconstruction. The first step is performed using a retrieval filter which roots in the derivative property of Fourier transform and takes into account the differential nature of DPC-CT projections. The second step is implemented by the classical fan-beam absorption-contrast filtered back-projection (FBP) algorithms. This work comprises a numerical study of the method and its experimental verification using a dataset measured with an X-ray DPC-CT system consisted of a three-grating interferometer and a mini-focus x-ray tube source. The results indicate that normalized root square error of the proposed method is 0.2532 and the reconstruction accuracy is improved 87% compared with direct FBP reconstruction.