1. An image processing apparatus, comprising: an image construction unit configured to output a plurality of different MPR images based on external image data acquired through image diagnosis equipment; a condition setting unit configured to set a priority order of display conditions for the MPR images; a displaying unit configured to display the MPR images at a plurality of image displaying areas including full image displaying areas and at least one evacuating image displaying area; a sorting unit configured to sort the plurality of MPR images into images for construction and images for evacuation based on the priority order of the display conditions, when a number of the MPR images exceeds a number of the image displaying areas; and a control unit configured to control display of the MPR images in the full image displaying areas and the evacuating image displaying area, and to reduce the images for evacuation into a predetermined size.