Assisting diagnosis performed by a doctor by calculating a first index value representing a direction and magnitude of motion of each portion of the heart for a three-dimensional anatomical image at a given phase of a three-dimensional anatomical image group representing a heart at each phase with respect to a further phase, calculating a second index value that serves as a diagnostic indicator of each portion of the heart from the three-dimensional anatomical image (7) at the given phase or the three-dimensional anatomical image group, generating a two-dimensional image (I) of the entire heart in which the second index value of each portion of the heart is disposed in a planar fashion, and displaying a mark (V i ) representing the first index value superimposed on the generated two-dimensional image (I) in a manner that allows the direction of motion of the first index value to be visually recognized.
