Constriction of cone-beam artifacts by the Z-smart reconstruction method

We introduce a novel approach for 3D image reconstruction from CB data acquired along a full circular trajectory. Our approach, which we refer to as the Z-smart reconstruction method, follows the scheme of ID filtering and 3D backprojection, while providing flexibility in the choice of the filtering directions. This flexibility allows us to modify the appearance of CB artifacts in the reconstruction results, so that, for certain imaging tasks, the Z-smart method can yield image quality that is significantly superior to that achievable with most other reconstruction algorithms for the full-scan circular trajectory. In particular, when imaging objects that have strong but localized heterogeneities in the axial direction, the Z-smart method can outperform both, the popular filtered-backprojection approach of Feldkamp et ah, and also ART, i.e. a fully 3D iterative reconstruction method. We provide a numerical evaluation of our algorithm using simulated CB data of an analytically defined tube phantom, with and without added noise.