The present disclosure discloses a medical image storing method, an information exchanging method, and apparatuses. A method includes: acquiring a medical image and a reference image, where the medical image and the reference image are images of a same region of a first object that are photographed at different times; determining an increment of the medical image relative to the reference image; and storing the increment of the medical image relative to the reference image. According to some embodiments of the present disclosure, an increment of a medical image relative to a reference image is determined, and only the reference image and the increment of the medical image relative to the reference image are stored, thereby reducing storage space occupied by a medical image.