1. A method for contrast-enhanced imaging of an object by an imaging device having a movable x-ray radiation source, which comprises the steps of: recording a first projection image sequence of the object along a first trajectory over which the movable x-ray radiation source moves, with a detector detecting x-ray radiation having a first energy spectrum; recording a second projection image sequence of the object along a second trajectory over which the movable x-ray radiation source moves, with the detector detecting x-ray radiation having a second energy spectrum, the first and second energy spectra being different energy spectra; reconstructing a three-dimensional subtraction image in relation to the different energy spectra using the first and second projection image sequences; reconstructing at least one two-dimensional subtraction image in relation to the different energy spectra by forward projection of the three-dimensional subtraction image; and providing the three-dimensional subtraction image together with the at least one two-dimensional subtraction image for an analysis of object characteristics.