A new scheme and reconstruction algorithm for dual source circular CT

Circular cone beam scanning has been a most popular scheme for computed tomography (CT) imaging, which is simple and can achieve symmetric projection data of the interested object. Many algorithms have been developed for circular cone beam CT. Many of these are FDK type algorithms, which can achieve good reconstruction quality when cone angle is small but may cause image deformation and density reduction at off plane when the cone angle is large. With the recently introduced dual source circular cone beam CT, we can deal with this problem under a new dual source geometry. In this paper, we propose a novel reconstruction scheme dual source circular cone beam CT by placing X-ray sources on two circular planes perpendicular to the rotating axis. We propose a reconstruction algorithm for this scanning scheme and evaluate the scanning scheme and the reconstruction algorithm with a 3D Shepp Logan phantom and a disk phantom. Simulation results show that the proposed method can provide improved reconstruction image quality for both in plane and off plane of the object. Index Terms—Dual source CT, circular cone beam CT, FDK algorithm.