A mammographic apparatus that includes X-ray detectors configured to detect X-rays entering the X-ray detectors, and attached to a holding-arm placed on a floor. The mammographic apparatus further includes circuitry configured to move the X-ray detectors between a scanning position and a waiting position. The X-ray detectors in the scanning position face an X-ray tube that generates X-rays across a breast-table, and the X-ray detectors in the waiting position are closer to the holding-arm than are the X-ray detectors in the scanning position.