PROBLEM TO BE SOLVED: To enable an appropriate comparative observation of an analyte (or a subject of analysis) by associating two radiographic images of right and left portions of a substantially right-left symmetrical portion, and by displaying the radiographic images of the right and left portions in a substantially right-left symmetrical manner.SOLUTION: An image processing device of the present invention includes: a right-portion image acquisition means for acquiring a three-dimensional radiographic image of a right portion of a substantially right-left symmetrical portion； a left-portion image acquisition means for acquiring a three-dimensional radiographic image of a left portion of the substantially right-left symmetrical portion； an alignment means for aligning the three-dimensional radiographic image of the right portion and the three-dimensional radiographic image of the left portion on the basis of a position of characteristic features of the portions； and a display controlling means for displaying the aligned three-dimensional radiographic image of the right portion and three-dimensional radiographic image of the left portion in a right-left symmetrical manner.SELECTED DRAWING: Figure 1【課題】 略左右対称な部位の右部位と左部位の放射線画像を関連付けて、右部位及び左部位の放射線画像を略左右対称に配置して表示させることで、被検体（又は、被検者）の適切な対比観察を行うことができる。【解決手段】 本発明に係る画像処理装置は、略左右対称な部位の右部位における３次元放射線画像を取得する右部位画像取得手段と、前記略左右対称な部位の左部位における３次元放射線画像を取得する左部位画像取得手段と、前記部位の特徴位置に基づいて、前記右部位の前記３次元放射線画像と前記左部位の前記３次元放射線画像との位置合わせを行う位置合わせ手段と、位置合わせされた前記右部位の前記３次元放射線画像と前記左部位の前記３次元放射線画像を略左右対称に配置して表示させる表示制御手段とを備える。【選択図】 図１
