Analytical geometric parameter calibration algorithm for cone-beam CT

Deviation of geometric parameter from its design value of cone-beam computed tomography (CT) would result in image quality degradation. An analytical geometric parameter calibration method for cone-beam CT system was developed to improve the accuracy. The algorithm uses few assumptions, a simple calibration phantom and several projections to analytically estimate the geometric CT parameters. Simulations and experiments demonstrate that the algorithm is very accurate with the offset of the projection position of the rotation center being less than 0.1 pixel. A sensitivity analysis shows the robustness of the algorithm which is easy to implement and of great practical significance.