To make it possible to control display of a label added to a three- dimensional image without placing a burden on the user. [Solution] Labels are added by a label adding unit (16) to structures such as a body surface region , a lung region , bronchial tubes , and pulmonary nodules of a person , extracted by a structure extraction unit (14) from a three- dimensional image (V0) of a chest. An image display control unit (18) causes a display unit (26) to display a volume rendering of the three- dimensional image (V0). At this time, a label display determination unit (20) determines a label to be displayed together with the displayed volume rendering image on the basis of a degree of transparency during the volume rendering display. The label display control unit (22) causes the display unit (26) to display the determined label together with the volume rendering image.
