<title>Challenges in providing general access to digitized x rays over the Internet</title>

Abstract

As part of a collaborative project with other government agencies, the National Library of Medicine (NLM) is engaged in the development of an electronic archive of digitized cervical and lumbar spine xrays taken in the course of nationwide health and nutrition examination surveys. One goal of the project is to provide access to the images via a client/server system specifically designed to enable radiologists located anywhere on the Internet to read them and enter their readings into a database at the server located at NLM. Another key goal is to provide general (public) access to these images, the radiologists' readings, and other collateral data taken during the survey. The system developed for such general access is based on a public domain server, the World Wide Web (WWW), and NCSA Mosaic, a distributed hypermedia client system designed for information retrieval over the Internet. This paper describes the design of the client/server software, the storage environment for the x-ray archive, the user interface, the communications software, and the public access archive. Design issues include file format, image resolution (both spatial and contrast), compression alternatives, linking collateral data with images, and the role of staging and prefetching.