1. A method, comprising: generating at least two CT image data sets of an object volume with different medium x-ray energies; calculating a new CT image data set using a weighted combination of the at least two CT image data sets, wherein a weighting factor, used in the weighted combination, is selected such that image artifacts in the new CT image data set are relatively reduced compared with image artifacts in the at least two CT image data sets, the image artifacts being caused by metal within the object volume, and the new CT image data set is obtained through calculation of a monoenergetic CT image data set with an x-ray energy, the x-ray energy of the monoenergetic CT image data set being selected such that the image artifacts in the new CT image data set are relatively reduced compared with the image artifacts in the at least two CT image data sets; and changing the weighting factor, by a user, to bring about an interactive change in the x-ray energy of the monoenergetic CT image data set when examining one or more images of the new CT image data set, wherein the interactive change has an effect on the images of the new CT image data set represented in real time.