A method for dual-energy spectra CT scanning and image reconstruction of two tomographic image datasets from a higher-energy and a lower-energy x-ray energy spectrum is disclosed. In at least one embodiment, readings are taken with the different x-ray energy spectra during the scanning the different x-ray energy spectra are also created at least by different acceleration voltages of the x-ray source and the spatial distribution of the scanning x-rays per x-ray energy spectrum is undertaken randomly or pseudo-randomly (in the absence of a regular pattern). With the attenuation datasets thus obtained, reconstructions of two tomographic image datasets in accordance with a least one iterative CS reconstruction method are carried out and subsequently the reconstructed tomographic image datasets are stored and/or output and/or further processed.
