1. Data processing device for performing a reconstruction of computed x-ray tomography (CT) data, wherein the computed tomography data is reconstructed from acquired CT data, the data processing device comprising: a detector comprising energy resolving detector elements configured to acquire at least a partial spectrum; a memory configured to store at least one of the acquired CT data and the computed tomography data, and a processor configured 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; rendering 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 that is different than an actual source trajectory when the at least partial spectrum is acquired.