A reconstruction unit (a pre-processor, a reconstruction unit and an image processor) generates a reconstruction image based on output from the X-ray detector. A correction parameter storage stores correction parameters in time series, the correction parameters being used for correction by which noise or artifact is reduced in processing performed by the reconstruction image unit. A correction parameter analysis unit determines whether or not an abnormal condition occurs based on a temporal change in the correction parameters stored in the correction parameter storage. A notification unit issues a notification indicating the occurrence of an abnormal condition where the correction parameter analysis unit determines that the abnormal state has occurred.