An image processing apparatus includes an index computing unit that computes motion functional indices of a particular organ from volume data of a subject including the particular organ, a polar map generating unit that generates a polar map by developing the indices on a polar coordinate system, an image generating unit that generates, from the volume data, an image related to a structure of one of the particular organ and a peripheral organ developed on the polar coordinate system, a fusing unit that fuses the image into the polar map, and a display unit that displays a polar map fused with the image.