A medical-use image data analyzing apparatus, aiming for detecting with a simple operation, presence or extent of difference in timing of movements among local portions as to facilitate diagnosis of diseases such as cardiac infarction, includes: an image input unit configured to input an image data of a test subject; a movement detector configured to detect movement of the test subject, based on the image data; a time distance calculator which calculates a time distance up to a time point when movement parameter, which is calculated from the movement, reaches local maximum or local minimum; a display device configured to display the time distances for the respective local portions of the test subject; and a memory.