Exact ROI image reconstruction with perturbed source trajectories in C-arm CT

In C-arm CT, the actual trajectory executed by the X-ray source may deviate from the designed scan due to mechanical error. Without taking into account this deviation, artifacts will appear in the reconstructed image. In this work, we propose to use the recently developed backprojection filtration (BPF) algorithm, which can accommodate general trajectories, to incorporate the deviation of the source trajectory. The preliminary studies demonstrate that this algorithm provides the exact image reconstruction in the case that the deviation of the source trajectory from the ideal trajectory can be measured.