An X-ray perfusion-image creating unit creates an X-ray perfusion image indicating blood flow dynamics in a certain organ from an X-ray projection image of a subject given with a contrast agent. An image correction unit extracts thickness information indicating the thickness of a myocardium from a three-dimensional image taken by an X-ray Computed Tomography (CT) apparatus. Moreover, the image correction unit creates a corrected perfusion image in which the thickness of the myocardium in the X-ray perfusion image is corrected, based on the thickness information. A display unit then displays the corrected perfusion image.