Fast reconstruction of flat region in a super-short scan based on MD-FBP algorithm

In circular cone-beam computed tomography (CT), although the minimum data filtered-backprojection (MD-FBP) algorithm has many significant applications, such as handling super-short scan problem, its reconstruction efficiency is limited by the heavy calculation of backprojection. In this paper, aiming at the image reconstruction of flat region in a super-short scan, an improved method based on MD-FBP algorithm is developed using an integral operation with fixed integral interval during the implementation of backprojection, which has an improvement in reconstruction efficiency and parallel performance compared with the original MD-FBP algorithm. It is found that if the thickness of the flat region is less than 0.0349 R (R is the scanning radius), the uncertainty of the method can be ignored. When the thickness of reconstructed region is a little fat, it can also be reconstructed by increasing the scanning radius befittingly. The results of numerical simulation and real data experiments have demonstrated the correctness and merits of the proposed method.