An image processing apparatus obtains a three-dimensional radiation image of a right region of substantially symmetrical regions, obtains a three-dimensional radiation image of a left region of the substantially symmetrical regions, performs alignment between the three-dimensional radiation image of the right region and the three-dimensional radiation image of the left region based on a feature position of the regions, and substantially symmetrically arranges and displays the three-dimensional radiation image of the right region and the three-dimensional radiation image of the left region which have been aligned.
