An MRI prep scan acquires plural sets of echo signals at a plurality of cardiac time phases which are mutually different from each other for each slice and used to generate a plurality of respectively corresponding prep images. Reference information is acquired and displayed for determining a first cardiac time phase and a second cardiac time phase on the basis of the prep images. The first and second cardiac time phases are set in response to an operators specification. An imaging scan section for acquiring imaging echo signals by performing an imaging scan is performed upon each of the first and second cardiac time phases to acquire imaging echo signals. A first image is generated based on an echo signal of the first cardiac time phase and a second image is generated based on an echo signal of the second cardiac time phase. A differential image is acquired by calculating a difference between the first image and the second image.
