A reference landmark extracting and pairing unit extracts reference landmarks from each of two three-dimensional medical images and forms reference landmark pairs, while a general landmark extracting unit extracts general landmarks. The landmark pair forming unit forms general landmark pairs using of a distance between each of the reference landmarks and the general landmarks, and also forms general landmark pairs from the remaining general landmarks using the distances from the general landmarks included in the general landmark pairs. A coordinate transformation parameter calculating unit calculates coordinate transformation parameters, based on the positional information of the reference landmark pairs and the general landmark pairs. A corresponding sectional view creating unit creates corresponding sectional views for the two three-dimensional medical images based on the coordinate transformation parameters, and by the display controlling unit the two corresponding sectional views are displayed on a displaying unit.
