Suppression of Artifacts Caused by Phase Errors and Noises in X-Ray Phase Computed Tomography

X-ray Differential phase contrast computed tomography (DPC-CT) is a useful tool to image internal structure of tested sample, especially for low-Z materials. The image quality of the DPC-CT slices is highly relevant to the retrieved DPC images. Due to the existence of phase unwrapping errors and phase errors induced by strong scattering materials in DPC images, DPC-CT slices suffers from information loss and severe artifacts. In the present research, iterative phase correction and threshold segmentation method is proposed to eliminate phase unwrapping error in DPC sinogram. Regularized phase retrieval method considering inter-frame noise impact is proposed to reconstruct high quality phase. Iterative reconstruction method with total variation is utilized to mitigate the artifacts caused by strong scattering materials. The proposed method is proved effective to improve the image quality in DPC-CT system.