CT imaging is performed twice (S1101), which is set as the normal number of rotaions, and a sinogram is corrected (S1102) based on the sinogram obtained by performing CT imaging twice. Since the cycles of data variation caused by respiration are controlled so as not to overlap one another, usually the data variations caused by respiration are eliminated by performing CT imaging twice. However, depending on irregularity in the respiration cycle of the subject, data variation components sometimes overlap at the same angle in spite of the fact that the cycles of data variation caused by respiration are controlled so as not to overlap one another. Therefore, when data variation components remain overlapped at the same angle, CT imaging is performed one additional time (S1104) and the sinogram is corrected (S1102) using the sinogram obtained by performing the additional CT imaging.
