A study of four minimization approaches for iterative reconstruction in X-ray CT

This paper compares four different minimization approaches for iterative reconstruction in CT:(1) iterative coordinate descent approach (ICD), (2) conjugate gradient approach (CG), (3) separable parabolic surrogate approach with ordered subsets (OS), and (4) convergent ordered subsets approach (COS). In addition to showing that all approaches result in the same final image, the paper gives an indication of the number of iterations and time to convergence for the studied approaches.