Backprojection-filtration image reconstruction from partial cone-beam data for scatter correction

In this work, we proposed a novel scatter correction method for a circular cone-beam computed tomography (CBCT) using a hardware-based approach that completes both data acquisition and scatter correction in a single rotation. We utilized (quasi-) redundancy in the circular cone-beam data, and applied the chord-based backprojection-filtratio (BPF) algorithm to avoid the problem of filterin discontinuous data that would occur if conventional filtered-backprojectio (FBP) algorithms were used. A single scan was performed on a cylindrical uniform phantom with beam-block strips between the source and the phantom, and the scatter was estimated for each projection from the data under the blocked regions. The beam-block strips (BBSs) were aligned parallel to the rotation axis, and the spacing between the strips was determined so that the data within the spaces constitute at least slightly more than the minimum data required for image reconstruction. The results showed that the image error due to scatter (about 30 % of the attenuation coefficien value) has been successfully corrected by the proposed algorithm.