A medical communication system developed at the University of Ottawa is presented in this paper. This system is intended to facilitate the communications between radiologists and physicians within a hospital. Radiographs are taken, digitized, and then stored in the database. Radiologists retrieve radiographic images from the database for diagnosis, and make diagnostic reports to be stored in the database. Physicians consult these radiographic images and diagnostic reports in order to provide the appropriate care for the patient. A realtime conference can be set up between a radiologist and a physician who are physically located in different locations, for discussing a particular case. Therefore, within the system, radiographic images can be retrieved from the database for diagnosis and conferencing. One of the most important factors of the system's performance is the system response time in particular for image display. This response time is basically dependent on the speed of the image storage system and the rate of the underlying communications network. A field trial has been scheduled for evaluating the system performance and user acceptability in a hospital environment. This paper presents a pretrial study of the packetized radiographic image transfers over local area networks. © 1989 IEEE