Image reconstruction is executed by using magnetic resonance signals obtained by asynchronous multi-slice dynamic imaging without using any ECG-gated technique to obtain a plurality of MR images for each time phase with respect to a plurality of cross-sections corresponding to sequential changes in radio-frequency pulse frequency. The heart of a subject to be examined in MR images in the same time phase is developed by being divided into a plurality of small regions, and a developed view representing the average value of pixel values in each of the small regions is generated. For example, the developed views in the respective time phases are continuously displayed in a time-series manner.