An injection part injects a contrast agent into a subject. An image acquiring part images the subject with the contrast agent injected, and acquires a plurality of image data with different imaging times. A pixel value calculator obtains a pixel value within a region of interest set in each of the image data acquired by the image acquiring part, for each of the image data. An injection controller controls injection of the contrast agent by the injection part in accordance with the pixel value obtained for each of the image data.
