PDA-based teleradiology system debuts

Current telemedical systems based on personal digital assistants are generally limited to access of patient medical records and basic image viewing. Such systems have as yet been unable to satisfy the image manipulation demands of teleradiology.

That may change as the result of work at the University of Patras in Greece, where researchers recently announced a PDA-based teleradiology system (Conf Proc IEEE Eng Med Biol Soc 2007;1:3090-3093). The small size and weight of PDA devices provide attractive advantages of convenience and portability.

"The proposed system introduces PDA-based image processing and analysis services for state-of-the-art, rich media teleconsultation in emergency situations within a hospital environment," said Pantelis Georgiadis, a Ph.D. candidate in the university's laboratory of medical physics.

Physicians gave the system passing grades in recent tests. Static image viewing was judged to be adequate, even though the screen size is much smaller than a desktop workstation.

Image processing on the system includes gray-scale manipulation and spatial filtering techniques. Image analysis incorporates a probabilistic neural network classifier currently capable of discriminating among three major types of human brain tumors with an accuracy of 86.66%, Geordiadis said.

"Physicians found the viewing quality of gray-scale images satisfactory," he said.

Image quality can be further enhanced by the use of integrated image processing algorithms, such as windowing and filtering.

"Full DICOM transfer and decoding support on the PDAs render the proposed system plausible in a wireless hospital environment," Geordiadis said.

Testing was achieved in a clinical department covered with WiFi using three IEEE 802.11b-compliant points providing wireless access to any standard client inside the cover range. Access points were placed 20 meters apart to ensure maximum cover range.

PDA application software was developed in MS Embedded Visual C++ 4.0. Each PDA can receive, load, process, and analyze high-quality static MR images. A 1-GB storage card installed on the PDA devices (HP iPaq rx3715) provided sufficient storage to handle test images, the average size of which was about 600 kB (512 x 512 gray-scale image). Transfer time from the DICOM server was approximately four seconds.

Georgiadis said data security was ensured by the use of several remote access technologies, including WEP (wired equivalent privacy), SSID (service set identifier), and MAC (media access control) authentication.

"To further enhance system security, a pass code authentication at application startup was implemented to prevent nonauthorized user access," he said.