Energy spectrum CT (Computed Tomography) iterative expansion and reconstruction system based on low-rank constraint

The invention relates to an energy spectrum CT iteration expansion reconstruction system based on low-rank constraint. The system comprises an information input module, an energy spectrum CT reconstruction network module and an information output module. In the information input module, energy spectrum projection data and system parameters are input, a low-rank constraint-based CT reconstruction problem is solved by adopting a primal-dual method, and an energy spectrum CT iterative reconstruction algorithm easy for neural network expansion is obtained; neural network expansion is carried out on each calculation step of the iterative reconstruction algorithm to obtain a sub-network structure of an iterative expansion reconstruction network, the energy spectrum CT reconstruction network is composed of a plurality of sub-networks with the same structure, the energy spectrum projection data sequentially passes through each sub-network to generate a reconstructed energy spectrum CT cross-sectional image, and in th