T Bazzill | PubMed Health

PubMed1995

Asynchronous transfer mode technology for radiologic image communication.

Image communication is an important component in picture archiving and communication systems (PACS) and teleradiology applications. Currently, local area networks (LANs) and wide area networks (WANs) use different technologies for image communication. Asynchronous transfer mode (ATM) is an emerging technology that can be used for both LANs and WANs. This article describes experimental results using an ATM network to transmit CT scans and digitized radiographs between the University of California, San Francisco (UCSF) and Mount Zion Hospital, an affiliated community hospital in the San Francisco Bay area. The WAN connection between the two hospitals is via an ATM main switch at Pacific Bell, a local communication carrier located in Oakland, CA, which uses single-mode optical fibers. Preliminary results show that, using the ATM Optical Carrier Level 3 (OC3) (155 Mbits/sec) specification, it takes 1.3 sec and 2.7 sec to transmit a 10-Mbyte digitized radiograph and a 20-Mbyte CT scan, respectively, between the two locations. Encouraged by these results, we have designed and implemented an ATM WAN and LAN between UCSF and Mount Zion Hospital. This is the first of a three-phase project of installing a WAN serving four hospitals and one clinic in the San Francisco Bay area.

Computer Communication Networks↗

PubMed1992

A fiber-optic broadband CT/MR video communication system.

Our department operates three magnetic resonance (MR) and three computed tomography (CT) scanners that are located in three different buildings up to 2 km apart. We have designed and implemented a multichannel, fiber-optic broadband video communication system as a remote scanner monitoring network. This system consists of baseband and broadband fiberoptic transmitters, receivers, and multiplexers. The structure of the video network is supported by two strategically located headends (distributors) connecting local/remote scanners and monitoring stations. The system is capable of serving up to 5 km from each headend. The video signal from each scanner is sent through a baseband fiber-optic link to a headend, where it is frequency modulated, multiplexed with other scanner video signals, and distributed over broadband fiber-optic links to monitoring stations. Each receiver consists of a demodulator, a channel selectable tuner, and a video monitor. The current design provides up to 16 scanner channels and 16 remote monitoring station connections. Monitoring stations are placed in 14 clinical locations including the following reading rooms: thoracic, neuro, abdomen, musculoskeletal, gastrointestinal, genitourinary, and pediatric radiology. A radiologist can use any of these 14 monitoring stations to view a patient's CT/MR images in real-time as they appear on any of the six scanner consoles. By selecting the proper channel assigned to a patient's scanner, the radiologist may monitor the examination while using the telephone to communicate with the technologist at the scanner site. This fiber-optic broadband video communication system has been integrated into daily clinical use for over 6 months.

Computer Communication Networks↗