A Dual-domain Regularization Method for Ring Artifact Removal of X-ray CT

TL;DR

This paper introduces a dual-domain regularization technique for effectively removing ring artifacts in CT images by correcting detector response inconsistencies and applying sparse constraints, resulting in improved image quality.

Contribution

The paper presents a novel dual-domain regularization model that jointly corrects detector response errors and suppresses ring artifacts, enhancing CT image quality beyond existing methods.

Findings

Outperforms existing methods in ring artifact removal

Preserves structural details and image fidelity

Effective on real photon counting detector data

Abstract

Ring artifacts in computed tomography images, arising from the undesirable responses of detector units, significantly degrade image quality and diagnostic reliability. To address this challenge, we propose a dual-domain regularization model to effectively remove ring artifacts, while maintaining the integrity of the original CT image. The proposed model corrects the vertical stripe artifacts on the sinogram by innovatively updating the response inconsistency compensation coefficients of detector units, which is achieved by employing the group sparse constraint and the projection-view direction sparse constraint on the stripe artifacts. Simultaneously, we apply the sparse constraint on the reconstructed image to further rectified ring artifacts in the image domain. The key advantage of the proposed method lies in considering the relationship between the response inconsistency compensation coefficients of the detector units and the projection views, which enables a more accurate correction of the response of the detector units. An alternating minimization method is designed to solve the model. Comparative experiments on real photon counting detector data demonstrate that the proposed method not only surpasses existing methods in removing ring artifacts but also excels in preserving structural details and image fidelity.