Image processing device and X-ray diagnostic apparatus

An image processing device, comprising:

• processing circuitry configured to
• sequentially acquire image data of a DSA image of time-sequential DSA images of an object,
• sequentially acquire, each time image data of a DSA image of a latest time phase is acquired, a parameter value for each pixel based on a temporal change of a pixel value of each pixel corresponding to a same region of the object in the sequentially acquired image data of the DSA image of the time-sequential DSA images of the object, the parameter value at each pixel being a value that represents a time at which a parameter satisfies a predetermined condition defined for the parameter and the parameter value at each pixel being a value that is fixed for each of the sequentially acquired image data as it is sequentially acquired and does not change thereafter, and
• sequentially generate, each time the image data of the DSA image of the latest time phase is acquired, image data of a parameter image in such a manner that identification information according to the parameter value of each pixel is assigned to each pixel corresponding to the same region.