The storage stores three-dimensional image data at a plurality of time points indicating the flexible site of a biological body. A reconstruction processor subjects the projection data to reconstruction processing to generate three-dimensional image data regarding the flexible site for each of a plurality of timing points. An extracting part extracts a plurality of construction sites constructing the flexible site from the image data. An analyzing part calculates positional information indicating the position of the first site in the plurality of construction sites extracted from the image data at the first timing point, and the position of the first site extracted from the image data at the second timing point. An image processor generates a plurality of medical images indicating temporal changes in the relative position of the second site in the plurality of construction sites to the first site based on the positional information. A display controller causes a display to display the plurality of medical images along the time sequence.
