1. An information processing apparatus comprising: an ROI acquisition unit configured to acquire a position of an ROI (Region Of Interest) in an object; a position/orientation acquisition unit configured to acquire a position and an orientation of a tomographic image acquired by an ultrasonic probe; a processing-target region acquisition unit configured to acquire a processing-target region defined based on the position of the ROI; a calculation unit configured to calculate a cross area between the processing-target region and the tomographic image based on the position and the orientation of the tomographic image; and a display control unit configured to display the tomographic image and an outline image indicating an approximate outline of a portion to be examined, and to display information indicating the cross region on the outline image.