APPARATUS, AND METHOD FOR AIDING DETERMINATION OF ATROCAR PORT POSITION, AND MEDIUM HAVING A TROCAR PORTPOSITION DETERMINATION AIDING PROGRAM STORED THEREIN

A point within a three dimensional region represented by volume data is set as a target point. A three dimensional angular range having the target point as its apex is set, and a plurality of line of sight vectors directed toward the target point are set within the three dimensional angular range. A plurality of projected images are generated by projecting the three dimensional region onto projection planes perpendicular to the line of sight vectors for each of the line of sight vectors. The generated projected images are arranged and displayed on a screen.