Wireless takes a byte out of info overload

The vast amount of data contained in today's diagnostic images creates a bandwidth problem at the hospital bedside. Streaming video technologies may help the logjam by bringing medical images to doctors through their PDAs, according to researchers in Japan.

Multidetector CT images, 3D images, and even videos all threaten to swamp the pipelines leading to the patient.

"Even a high-bandwidth Ethernet LAN connection cannot handle the bandwidth of raw, uncompressed full-screen/full-motion video," said Dr. Norio Nakata, a radiology researcher at Jikei University in Tokyo.

Nakata's solution to the bandwidth problem is streaming media technology over a wireless medium. Although not yet available in the U.S., third-generation wireless technology has been used in Japan since 2001. It boasts data transfer speeds of up to 384 kbps, with 2-Mbps speeds expected in the future.

"Streaming video technology is one solution to the heavy network storage requirements and problems associated with medical images in a hospital," Nakata said.

At an infoRAD exhibit that received a certificate of merit, Nakata presented the results of a feasibility study that involved sending medical images over third-generation wireless technology to PDAs.

Nakata used the Pocket PC and Windows media viewer to see multidetector CT and MR DICOM files, as well as audiovideo interleave (AVI) format ultrasound files. To prepare the files for transmission as streaming video, they were encoded into Wndows media audio (WMA) format and could be stored in a Web server.

Requested files could then be downloaded from the Web server. An Internet browser could read the URL of the video file, and the requested file would be sent to the media player for viewing.

The process would be the same for images to be sent outside the hospital, he said, except the files would be requested and sent via a third-generation wireless connection.

For this type of a solution to provide readable images, the maximum resolution for PDA viewing is 320 x 240 pixels, although 640 x 480-pixel resolution displays should be available in the near future. The limit for wireless transmission data rates is 225 to 768 kbps for the IEEE 802.11b wireless technology and 225 kbps for third-generation wireless technology.

Physicians might soon use PDAs and streaming video technology for emergency telecommunications and teleradiology, bedside presentation of medical images, access to digital patient records, and for educational purposes, according to Nakata.

"I think that in two years, streaming media technology will change medical education at the RSNA meeting," he said.