PROBLEM TO BE SOLVED: To provide an image processing device for improving the accuracy of image processing of a subsequent stage even in the case that there is a loss or error of time phase information in image data.SOLUTION: The image processing device includes an acquisition part 1010 for acquiring an image picked up by contrasting a subject, a first region extraction part 1040 for extracting a first region representing a first anatomical portion of the subject from the image, an estimation part 1060 for estimating a state about density value change in a time series of the image from the first region, and a second region extraction part 1070 for extracting a second region representing a second anatomical portion of the subject from the image on the basis of an estimation result by the estimation part 1060.SELECTED DRAWING: Figure 1
