First magnetic resonance imaging (MRI) three-dimensional heart image data includes a plurality of two-dimensional heart image data superimposed and having a resolution in at least one direction that is different from that in two other directions. A first axis is detected in the three-dimensional heart image data. A first vector is calculated as passing through the first axis and having at least a predetermined resolution and generated image data on a plane passing through the first axis and the first vector is generated from the first imaging data. A second axis is detected relating to the heart from the generated image data, the second axis being a higher precision axis than the first axis.
