An image data correcting device has a movement information acquiring section, a correcting section and a synthesizing section. The movement information acquiring section acquires movement information showing spatial distribution of the magnitude of a movement in the real space of an image pickup part of a detected body. The correcting section makes a correction different from that of a second area in a first area of image data collected by a scan of magnetic resonance imaging on the basis of the movement information. The synthesizing section synthesizes respective image data of the first area and the second area corrected by the correcting section.