Implementing a MIRC query interface for a database driven teaching file

This paper describes the authors' experience with integrating an existing database-driven teaching file with the RSNA (Radiological Society of North America) Medical Imaging Resource Center (MIRC). MIRC is the product of an RSNA-sponsored initiative to enable medical institutions to share their electronic medical content (images, text, and multimedia) by creating a distributed repository accessible from the Internet. An existing database-driven teaching file, developed by the authors and used extensively by the University of California San Francisco (UCSF) Department of Radiology since 1998, was retrofitted to include an interface for handling broadcast queries initiated by a MIRC query service. These queries take place through the exchange of XML documents via HTTP. After all the storage services have responded, the results are collated by the query service and presented to the user. The teaching file and MIRC interface were developed using the 4th Dimension Relational Database Management System (RDBMS). The integration process primarily involved mapping the "MIRCdocument" schema to the teaching file's schema, translating the actual MIRC query into the internal query language of the database and extending the access control mechanisms of the teaching file to allow public access. A working implementation of the interface required only 3 days of development time, with refinements taking place over several months. Interface development was greatly aided by MIRC's use of well-established Internet standards. This project has demonstrated the feasibility of implementing a MIRC interface on an existing teaching file server.