1. A system for assisting preparation of medical-image reading reports, comprising: a medical-image storage unit archiving medical-image data; a medical-image reading report storage unit archiving a medical-image reading report; a collection unit configured to collect a character string of annotation data contained in the medical-image data or a character string associated with the medical image in the medical-image reading report, or both, from the medical-image storage unit or the medical-image reading report storage unit, or from both; a display unit configured to display the medical-image reading table or a reference image, or both, on a display screen; a display control unit configured to cause the display unit to display, at the same time, the medical image referred to while photographing an object and a list showing the character string; a selection unit configured to restrict the selection of the character string collected; an association unit configured to cause the selection unit to select a desired character string from the list, thereby associating the character string selected with the medical image; an input unit configured to insert the character string and the medical image associated to each other by the association unit, at a prescribed position on a report preparation screen, thereby preparing the medical-image reading report; and a data archiving unit configured to archive the image data representing the medical image associated with the character string inserted.