According to one embodiment, an image processing device includes processing circuitry. The processing circuitry sequentially acquires image data of time-sequential DSA images of an object, and acquires a parameter value for each pixel based on temporal change of a pixel value of the each pixel corresponding to the same region of the object in the sequentially acquired image data of time-sequential DSA images. Further, the processing circuitry sequentially generates image data of parameter images in such a manner that identification information according to the parameter value is assigned to the each pixel corresponding to the same region of the object, each time image data of a DSA image of the latest time phase being acquired.