A medical image system includes: a storage unit which stores a first medical image; a selection unit which selects a medical image to be associated with a second medical image; a designation unit which designates an abnormal shadow candidate; a reception unit which receives the second medical image newly created; a determination unit which determines whether or not the first medical image selected is an image suited for association, and the abnormal shadow candidate designated and the second medical image received satisfy a predetermined condition; an association unit which stores the second medical image in association with the abnormal shadow candidate; and a monitoring unit which monitors the association, outputs a warning, and stores the abnormal shadow candidate or the second medical image in association with information indicating there is no second medical image or abnormal shadow candidate to be associated, respectively.