1. Data processing device for performing a reconstruction of computed tomography data, wherein the computed tomography data is reconstructed from acquired CT data comprising at least a partial spectrum acquired by using a detector comprising energy resolving detector elements, wherein a memory is provided for storing at least one of the acquired CT data and the computed tomography data, and wherein a processor is provided which is adapted to perform at least the following operation: determining a wave-vector transfer by using the at least partial spectrum; determining a reconstruction volume; wherein a dimension of the reconstruction volume is determined by the wave-vector transfer; wherein the wave-vector transfer represents curved lines in the reconstruction volume; and rearranging the acquired CT data such that it corresponds to an acquisition along a desired source trajectory in the reconstruction volume.