A penalized weighted least-squares image reconstruction based on scatter correction methods for X-ray CT

For metal artifact reduction (MAR) in X-ray cone-beam computed tomography (CBCT), we propose a penalized weighted least-squares (PWLS) image reconstruction method [1] based on scatter correction (SC) method. Our main contribution is to incorporate the inaccuracy of the scatter correction data in PWLS method, and to accelerate the PWLS image reconstruction with a preconditioned conjugate gradient (PCG) method [2]. The reconstruction results of both the simulation and experimental data show that our proposed method effectively reduces the metal artifacts (MA). Compared to the state of art, normalized metal artifact reduction (NMAR) method [3], our method prevents the introduction of some new artifacts due to an inappropriate interpolation possible used in NMAR.