A storage unit stores data of a plurality of previous images of a plurality of regions generated during a previous catheter procedure. A route map generating unit arranges a plurality of first catheter images or blood vessel images included in the plurality of previous images according to the positional relationship between the plurality of regions to generate a route map indicating the distribution of the plurality of first catheter images or blood vessel images. A specifying unit specifies a specific portion of a second catheter image included in a current image generated during a current catheter procedure. A calculating unit calculates the position of the specified specific portion on the route map on the basis of the positional relationship between the current image and the previous image. A display unit displays a specific previous image corresponding to the calculated position.