Multi-view scatter estimation for moving blocker scatter correction of CBCT

The moving blocker method is economic and effective for scatter correction (SC) of cone-beam computed tomography (CBCT). However, at the regions with large intensity transition in the projection images in the axial blocker moving direction, the estimation of scatter signal from blocked regions in a single projection view can produce large errors, which can cause significant artifacts in reconstructed images and null the usability of these regions. In this work, we propose to use the adjacent multi-view projection images to jointly estimate scatter signal more accurately. The experimental results using CatPhan600 CBCT data show that the new method can effectively suppress the estimation errors of scatter signal and lead to much improved image quality in these regions. This development will expand the utility of moving blocker-based SC for the target with sharp intensity changes in the projection images, such as bone/lung and body/air interfaces.