FBP embedded iterative method to efficiently solve the low-dose CT

Low-dose X-ray CT is the reconstruction under the less X-ray intensity. In exchange for the intensity reduction, the noise level increases relatively. It is known that the Statistical Iterative Reconstruction (SIR) method is e?ective in reducing the image degradation due to the noise. One of the SIR formulations is the penalized weighted least squares (PWLS). Since the PWLS requires a large computational cost, the acceleration method such as the Iterative FBP (IFBP) has been studied. However, IFBP cannot exactly minimize the PWLS cost function. This paper shows a new acceleration method for e?ciently solving the PWLS problem. Based on the Alternating Projection Proximal (APP) method, our approach exactly solves the PWLS. The design of the FBP filter is also presented. The reconstruction of the chest X-ray image is carried out. It is shown that the proposed method can give the highly acceleration and the exact solution.