A shadow area in a lung-field area of a subject is detected from tomographic images constituting a three-dimensional image representing the subject. A hilum-of-lung area in the lung-field area of the subject is detected from the tomographic images. Further, a slice image that passes through a first point that is a predetermined point in the detected shadow area, a second point that is a predetermined point in the detected hilum-of-lung area, and an arbitrary point that has been set in advance is generated. The generated slice image is displayed.
