The invention relates to a projection values processing apparatus (1) for processing acquired projection values. A first image is reconstructed from acquired projection values under consideration of a reconstruction assumption by a reconstruction unit (13). A simulated projection values determining unit (14) determines simulated projection values by simulating a projection through the reconstructed first image under consideration of the reconstruction assumption, and inconsistency values are determined for the acquired projection values by an inconsistency determining unit (15), wherein an inconsistency value is indicative of a degree of inconsistency of a respective acquired projection value with the reconstruction assumption, by comparing the acquired projection values and the simulated projection values. The inconsistency values can be used for different purposes, for example, improving the quality of a reconstructed image or indicating image elements being affected by an inconsistency between reconstruction assumption and acquired projection values.