Filtering path variable FDK (v-FDK) reconstruction algorithm for circular cone-beam CT

The FDK algorithm has played an important role in both biomedicine and industry because of its celerity and simplicity for the reconstruction of CT images. However, artifacts and attenuation may occur in FDK reconstruction under large cone angle with circular trajectory owing to the insufficient data. In this paper, a factor k is introduced to change the projected surface, based on the idea of rebinning algorithm. In that case, the path of filtering was arbitrarily changed and a unified pre-weighting formula was presented, which consequently enable the filtering path variable FDK (v-FDK) to be smoothly converted to P- FDK and T-FDK by tuning the k factor. Numerical simulations demonstrated our proposed algorithm an effective method for improving the reconstruction accuracy especially in the case of large cone-angles. On top of that, an optimal k value was found which can be used to obtain a reconstructed image with better quality than the image obtained by P-FDK and T-FDK.