A remote conference system for image diagnosis on the World-Wide Web

Consulting with radiologists outside the hospital by using Java

A Java-based teleradiology system that makes use of the Internet has been developed. Using this system, an on-call, off-duty radiologist can make diagnoses and perform consultations easily by reviewing the transferred images at home. The image accessibility of the system allows a hospital with such a system to assist an affiliated rural hospital without a full-time radiologist. The system consists of three components: the image server subsystem, the database server subsystem, and the client subsystem. All client subsystems of the system are designed to be symmetric. Users may retrieve images, manipulate them, and perform remote consultations. In addition, a user may add annotations to an image area of interest. Screen synchronization is achieved by means of the command-passing technique and local command execution to reduce the network bandwidth and transmission demands; user interaction is achieved by means of a synchronized indicator for pointing out areas of interest and dialog windows for conversation. Because Java programs can run on heterogeneous platforms, the need for system maintenance and user training is minimized. Although the drawback of Internet bandwidth still exists, the system enables platform-independent teleradiology via the Internet and allows easy and cost-effective remote consultation.

Secure transmission of urologic images and records over the Internet

PURPOSE

Telemedicine has become a common method for the transmission of images and patient data across long distances. Our goal was to assess the efficiency and accuracy of Photomailer MD software, a store-and-forward telemedicine system, in the urologic setting.

METHODS

Photomailer MD software was loaded on two computers in the host institution, one with a T1 connection to the Internet and the other with a dial-up modem connection (24,000 bits/second), and computers at three remote sites. A total of 14 clinical cases, comprised of digitized histories and radiographic images, were sent to the remote institutions four separate times using the four transmission modes available: nonencrypted, 56-bit encryption, 128-bit encryption, and 128-bit encryption with password. The following data points were recorded: file size before and after encryption, file transmission times, and diagnostic accuracy of the remote urologists. One-way ANOVA was used to compare mean values statistically, while the z-test was used to compare diagnostic accuracies.

RESULTS

Encryption increased the file size by a mean of 37.8%, with the three encryption modes increasing file sizes by the same number of kilobytes. When a dial-up modem was used, encrypted files required a significantly longer transmission time (P < 0.05) than the unencrypted files. The same trend was seen with the T1 connection, although the differences often were not significant. When T1 transmission times were compared with modem times with other variables held constant, modem times were significantly longer (P < 0.05). Diagnostic accuracies for each of the three remote centers ranged from 85.7% to 100%. Differences in accuracy rates between attending physicians and residents were not significant.

CONCLUSIONS

Photomailer MD provides a secure, convenient, and affordable method of transmitting patient images and records via the Internet. Transmission speed was significantly greater when using a T1 line and also tended to be faster when files were not encrypted. There was no significant difference in transmission time among the three encryption modes; therefore, 128-bit encryption with a password should be used to maximize security. Diagnostic accuracies were comparable to those in the literature. In general, 640 x 480-pixel resolution was adequate for urologic diagnoses, although higher-resolution images may improve accuracy.