Aspects include estimating structure models for a voxel(s) of a spectral image. The estimation is based on a noise model. Aspects further include fitting structure models to a 3D neighborhood about the voxel(s), selecting one of the structure models for the voxel(s) which is based on the fittings and predetermined model selection criteria. Aspects further include de-noising the voxel(s) based on the selected structure model, which produces a set of de-noised spectral images. Other aspects include generating a virtual contrast enhanced intermediate image for each energy image of a set of spectral images. The energies correspond to different energy ranges which are based on de-noised spectral images, decomposed de-noised spectral images, an iodine map, and a contrast enhancement factor. Aspects further include generating final virtual contrast enhanced images. The final virtual contrast enhanced images are generated by incorporating a simulated partial volume effect with the intermediate virtual contrast enhanced images.
