Wireless networks free up radiology departments, within limits

Unfettered by wires or workstations, radiologists stroll through the hospital, viewing medical images and signing off on reports. But physical limitations and security issues still pose hurdles to large-scale implementation of wireless solutions.

"Wireless networks are becoming more affordable and available," said Dr. Khan Siddiqui, a radiology fellow at Geisinger Medical Center in Danville, PA. "Penetration is still slow in the hospital environment, and it is almost nonexistent in the radiology department."

Siddiqui and colleagues examined the feasibility of using PDAs with wireless local area network (WLAN) capability within the radiology department. They used the 802.11b wireless network protocol and a dynamic wireless encryption protocol for security. They gave two different PDAs and two different tablet PCs to four radiologists and four residents.

All the study participants had more than two years' experience using PDAs. After evaluating the devices for two weeks, they answered an online questionnaire.

Siddiqui reported that the WLAN provided full network coverage, with occasional lockouts when the devices moved out of range. The users achieved an average network speed of 2 Mbps.

The study participants found the PDA to be more portable than the tablet PC, but the expansion pack needed for WLAN access made the devices bulky. They rated image quality better on the tablet PC than on the PDA.

Image quality on a small PDA was not adequate for primary image interpretation, but signing reports was feasible on all of the devices, Siddiqui said.

The users considered the ability to sign reports and use e-mail at will to be among the best features of the devices. The large size and short battery life were the worst features, they reported.

Dr. Peter Gocke at University Hospital of Essen in Germany studied the use of tablet PCs for wireless image distribution. Two tablet PCs were distributed to each of six hospital wards.

"As soon as we implemented PACS in the hospital, we had a dramatic change in how images were viewed," Gocke said.

Images became available only where hardware allowed physicians to view them. The use of tablet PCs with wireless network access increased those opportunities, he said.

Gocke and colleagues added 802.11 a/b/g access points throughout the wards and configured the tablet PCs to access the PACS Web server for image and report delivery.

"Wireless networks are more complex then wired networks, especially in terms of security," he said.

Gocke listed several steps that network administrators should take to ensure a minimum of network security:

· disable service set identifier (SSID) broadcasting
· enable media access control (MAC) address filtering
· use wireless encryption protocol (WEP) 128-bit , not 64-bit, keys
· use virtual private networks (VPNs)
· place a firewall between the wireless and the wired network

Even with all these measures in place, security remains an issue. Sending patient information over wireless networks is still somewhat restricted in Germany, Gocke said. The arrival of 802.11i should address many current security concerns.

The study participants successfully accessed clinical images at the patient's bedside. The popularity of the tablet PCs, measured by an opinion poll, contributed to greater acceptance of IT systems in the hospital, Gocke said.