Transparent image access in a distributed picture archiving and communications system: The master database broker

A distributed design is the most cost-effective system for small- to medium -scale picture archiving and communications systems (PACS) implementations. However, the design presents an interesting challenge to developers and im plementers: to make stored image data, distributed throughout the PACS netw ork, appear to be centralized with a single access point for users. A key c omponent for the distributed system is a central or master database, contai ning all the studies that have been scanned into the PACS. Each study inclu des a list of one or more locations for that particular dataset so that app lications can easily find it. Non-Digital Imaging and Communications in Med icine (DICOM) clients, such as our worldwide web (WWW)-based PACS browser, query the master database directly to find the images, then jump to the mos t appropriate location via a distributed web-based viewing system. The Mast er Database Broker provides DICOM clients with the same functionality by tr anslating DICOM queries to master database searches and distributing retrie val requests transparently to the appropriate source. The Broker also acts as a storage service class provider, allowing users to store selected image subsets and reformatted images with the original study, without having to know on which server the original data are stored. Copyright (C) 7999 by W. B. Saunders Company.