A structure extraction unit extracts a heart region from a three-dimensional image of a chest, an image display control unit displays a volume rendering of the extracted heart region, an information adding unit adds additional information such as text and voice to a VR image displayed according to desired display conditions which include an image orientation. The display conditions when the additional information is added are stored with the additional information as designated display conditions. An allowable range setting unit sets a predetermined allowable range for the designated display conditions. During subsequent display of the VR image, an information reproducing unit enables the added information to be reproduced when display conditions are within the allowable range of the designated display conditions.
