Anisotropic total variation minimization approach in in-line phase-contrast tomography and its application to correction of ring artifacts**Project supported by the National Natural Science Foundation of China (Grant Nos. 61671004, 61271012, 81371549, 81671683, and 11501415), the Natural Science Foundation of Tianjin City, China (Grant No. 16JCYBJC28600), the WBE Liver Fibrosis Foundation of China (Grant No. CFHPC20131033), the Instrument Developing Project of

Abstract

In-line phase-contrast computed tomography (IL-PC-CT) imaging is a new physical and biochemical imaging method. IL-PC-CT has advantages compared to absorption CT when imaging soft tissues. In practical applications, ring artifacts which will reduce the image quality are commonly encountered in IL-PC-CT, and numerous correction methods exist to either pre-process the sinogram or post-process the reconstructed image. In this study, we develop an IL-PC-CT reconstruction method based on anisotropic total variation (TV) minimization. Using this method, the ring artifacts are corrected during the reconstruction process. This method is compared with two methods: a sinogram preprocessing correction technique based on wavelet-FFT filter and a reconstruction method based on isotropic TV. The correction results show that the proposed method can reduce visible ring artifacts while preserving the liver section details for real liver section synchrotron data.