Accurate Iterative FBP Reconstruction Method for Material Decomposition of Dual Energy CT

Compared with traditional CT, dual energy CT (DECT) has the capability to improve material differentiation and reduce beam hardening artifacts, and thus has wide prospects of applications. In this paper, by linearizing the polychromatic projections with their first-order Taylor expansions, we derive an iterative reconstruction method for DECT. The method updates the basis material images by adding the residual images reconstructed from the residual projections to the current estimated basis material images, i.e., the iteration process of the proposed method is carried out in image domain, so it is applicable to both geometrically consistent and inconsistent projections. In addition, as the filtered back-projection method is used in the reconstruction of the residual images, the proposed method has a high degree of parallelism. Both numerical simulation and real-data experiments are performed, and the results confirm the effectiveness of the proposed reconstruction method.