Ring artifact corrections in flat-panel detector based cone beam CT

摘要

The use of flat-panel detectors (FPDs) is becoming increasingly popular in the cone beam volume and multi-slice CT imaging. But due to the deficient semiconductor array processing, the diagnostic quality of the FPD-based CT images in both CT systems is degraded by different types of artifacts known as the ring and radiant artifacts. Several techniques have been already published in eliminating the stripe artifacts from the projection data of the multi-slice CT system or in other words, from the sinogram image with a view to suppress the ring and radiant artifacts from the 2-D reconstructed CT images. On the other hand, till now a few articles have been reported to remove the artifacts from the cone beam CT images. In this paper, an effective approach is presented to eliminate the artifacts from the cone beam projection data using the sinogram based stripe artifact removal methods. The improvement in the required diagnostic quality is achieved by applying them both in horizontal and vertical sinograms constituted sequentially from the stacked cone beam projections. Finally, some real CT images have been used to demonstrate the effectiveness of the proposed technique in eliminating the ring and radiant artifacts from the cone beam volume CT images. A comparative study with the conventional sinogram based approaches is also presented to see the effectiveness of the proposed technique.