A Computer-Aided Diagnosis (CAD) apparatus for correctly detecting a nodule is provided. The CAD apparatus includes an input device for receiving a first image captured by emitting X-rays towards a user and a second image that is discriminated from the first image and is an image of the user an information acquisition device for acquiring a bone model of the user by using the second image and a CAD device for compensating for the first image by using the bone model.
