In one embodiment, there is provided a dynamic multi-source image reconstruction apparatus. The apparatus includes a first reconstruction stage, a second reconstruction stage, and a refinement stage. The first reconstruction stage is configured to receive an input data set including a group of data frames. Each data frame corresponds to a respective time step. Each data frame includes a number of projection data sets. Each projection data set corresponds to a respective source-detector pair of a stationary multi-source tomography system. The first reconstruction stage is further configured to reconstruct a first intermediate image based, at least in part, on the group of data frames. The second reconstruction stage is configured to receive a selected data frame and to reconstruct a second intermediate image with a constraint of the first intermediate image as prior. The refinement stage is configured to refine the second intermediate image to produce a three-dimensional output image.