According to one embodiment, storage unit stores three-dimensional function image data concerning a function index of the heart. The extraction unit extracts a myocardial region from the three-dimensional function image data. The normalization unit normalizes the distance between the inner wall and outer wall of the myocardial region with a predetermined numerical value range. The generation unit generates a bull's eye map expressing a spatial distribution of pixel values at positions on the myocardial region by two-dimensional polar coordinates. The positions correspond to predetermined values in the predetermined numerical value range. The display unit displays the bull's eye map.