Teleconferencing for cost-effective sharing of radiology educational resources: potential and technical development

To develop a cost-effective method of sharing educational resources, a dial-up teleconferencing network was implemented between three radiologic sites for a 30-day period of evaluation. By means of standard dial-up telephone channels, compressed video and audio signals displayed radiologic images, slides, and text, allowing residents and faculty from the three sites to participate in sight and sound interactions. Each of the three sites used compressed video/audio coder-decoders (codecs) conforming to the Consultative Committee on International Telegraphy and Telephony H.261 standard. Four video cameras were used at each site, and the audio was run in full duplex mode. A multipoint video bridge was used to broadcast codec output signals to the input lines of the other codecs. Our evaluation found audio quality to be suboptimal, but capable of being improved; diagnostic image quality was adequate when a video zoom mode was used; the digital-archive mode of the codec proved advantageous; the H.261 codec permitted participation from all sites; and all conference lecturers were able to conduct their conferences as they were accustomed. Although audio quality and spatial resolution need to be improved, the results of this pilot study imply that dial-up compressed video conferencing has the potential to become a practical, cost-effective method of sharing educational resources by means of interactive radiologic multisite educational programs.