There are provided: a region extraction unit that extracts a plurality of regions from a three-dimensional image of a subject an internal tissue information acquisition unit that sets, as a crossing region, a region that a light beam used when projecting the three-dimensional image onto the two-dimensional projection plane crosses first among the plurality of regions, sets, as a first intersection, a point on a region crossing the light beam first when the crossing region is excluded, sets, as a second intersection, a point crossing the crossing region when there is an extension in an opposite direction to a traveling direction of the light beam from the first intersection, and acquires information of an internal tissue included between the first and second intersections and a display control unit that displays the internal tissue information so as to be superimposed on the three-dimensional image.
