The present disclosure relates to a system and method with which an imaged range in the past can be reproduced with high precision. In accordance with certain embodiments, an X-ray CT apparatus includes a camera-image producing section for producing a first camera image of a patient, a landmark fixing section for fixing a landmark with reference to a chest of the patient, and an imaged-range defining section for defining a first imaged range in a first scan based on landmark data representing the landmark. The camera-image producing section acquires a second camera image of the patient in a follow-up examination, the landmark fixing section fixes a second landmark with reference to the chest of the patient contained in the second image, and the imaged-range defining section defines second imaged range in a second scan based on landmark data representing the landmarks, and imaged-range data representing the first imaged range.