The position of a sensitive area specified by a sensitive area specifying unit (13), and the position of a plurality of overlapping regions specified by an overlapping region specifying unit (14) are simultaneously displayed in a display region of an elongated image in an operating panel (11). A display prompting confirmation of a number of divisions for the operating panel (11) is performed by a confirmation display unit (16). When the position of the sensitive area and the position of the plurality of overlapping regions are superposed, the length of a rectangular imaging region in the body axis direction of a test subject is reduced, and the number of divisions in the elongated image is increased by one by increasing the number of rectangular images by one.
