PROBLEM TO BE SOLVED: To display a three-dimensional position of a feature region on a three-dimensional image using a two-dimensional image with a high degree of precision.SOLUTION: In an X-ray imaging apparatus 101, a feature region extraction part 109 acquires a feature region of a treatment instrument from a captured perspective X-ray image, a three-dimensional position calculation part 113 calculates a three-dimensional position of the feature region, and an image alignment part 112 aligns a three-dimensional image captured beforehand with the captured perspective X-ray image, adds the three-dimensional position on the three-dimensional image, and displays the perspective X-ray image and the three-dimensional image so as to make the positional relationship between a lesioned part and the treatment instrument clearer.SELECTED DRAWING: Figure 1
