1. A method for evaluation of propagation of information in prior-image-based reconstruction, the method comprising: providing an objective function, wherein the objective function comprises a second term representing a generalized image penalty that discourages roughness in the reconstruction through use of one selected from a group consisting of a gradient applied to an image volume, a sparsifying operator applied to an image volume, a combination thereof, or a p-norm metric; and decomposing the objective function into a first component dependent at least on current imaging data and a second component dependent at least on prior imaging data.