PROBLEM TO BE SOLVED: To provide improvement technologies for display of images obtained through reconstruction processing.SOLUTION: A reconstruction processing unit 20 extracts a plurality of tomographic images, which periodically correspond to each other, from a plurality of tomographic image data with a plurality of periods stored in a preceding memory 14 and forms each reconstruction image data from the plurality of tomographic images, which periodically correspond to each other, to store the data in a subsequent memory 26. A mask processing unit 30 determines an attention region by mask-processing regions other than the attention region including objects in each reconstruction image data. A display processing unit 40 forms display images with images in the attention region successively acquired from a plurality of reconstruction image data at a plurality of time phases arranged at certain positions, displaying these display images on a display unit 42.
