An image processing apparatus has an extraction unit, a base calculation unit, a recommended-region calculation unit and a display unit. The extraction unit extracts a region including a branch artery of a subject based on volume data. The base calculation unit calculates a base of the branch artery based on the region including the branch artery. The recommended-region calculation unit calculates a recommended region for placing a balloon of a balloon catheter based on the volume data and the base. The display unit aligns and displays the recommended region on a basic image.
