Influence of the teleradiology technology (N-ISDN and ATM) on the inter-hospital management of neurosurgical patients

We set out to assess the influence of a teleradiology network on the relati ons between a general hospital and a 100 km distant university hospital in the context of neurosurgical emergencies, and compared a commercially avail able technology, N-ISDN (Narrowband Integrated Service/Digital Network), to an emerging technology, ATM (Asynchronous Transfer Mode). The evaluation w as conducted using records of advice request calls and patient transfers. T hree phases were considered: without teleradiology, with transfer of digiti zed images over N-ISDN at 64 kbps, and with an experimental ATM network at 10.5 Mbps with DICOM image transfers and videoconferencing. Additionally, s taff meetings over ATM videoconferencing were set up. To assess the ATM ser vice, we used log files and questionnaires. 108 advice requests were studie d over a 18 month period. The average transmission time for one examination was 38 s with full DICOM image resolution over ATM, versus 150 s with 10:1 JPEG (Joint Photographic Expert Group) compression over N-ISDN. Up to 50% unnecessary patient transfers were avoided. Advice requests increased fourf old, and non-urgent advice requests increased from 0 to 21%. Despite the ex perimental configuration of the ATM network, the service gave satisfaction to all the physicians. Videoconferencing was unanimously regarded as a prom inent tool to improve the quality of interaction. It was particularly usefu l for non-urgent cases and distant staff meetings. Teleradiology can improv e the relations between hospitals through an increase of urgent and non-urg ent advice requests. Asynchronous transfer mode is an efficient way for fas t transfer of radiological examinations in DICOM format and for discussing them through high-quality videoconferencing.