| After a decade of research and development a successful, full hospital Picture Archive and Communication System (PACS) is still not a reality. Two technical factors continue to limit the success of PACS: the lack of effective information management in storage components and the performance limitations of conventional communication networks.;The association information relating sets of images must be maintained along the communication path from image source, through storage, to image sink. A PACS must also present a logical and familiar organization of information to its users. By creating electronic analogs of a folder, both of these goals can be met. A folder is defined first as a communication structure using a nested entity relation model. Mappings may be defined from the nested model to a relational model, resulting in a database schema. This schema and the techniques for mapping between data models provide solutions to the key problems of modality directory normalization and unbounded database growth.;The image throughput performance of PACS components is determined more by the speed of storage devices, system buses, and network interface cards than by the physical signaling rate of the network used to connect them. Two approaches to high speed image communication are examined: broad band ISDN and a Shared File System model. In both cases care was taken to eliminate the performance bottlenecks in all attached nodes with the result that high signaling rate networks provide high image throughput.;The problem of image prefetch must be solved if PACS are to become clinically useful. Prefetch can be divided into two problems: prefetch for primary radiology diagnosis and prefetch for clinical use. IPE, a prototype expert system has been developed to permit the selection of an appropriate subset of archived patient image data needed to correctly diagnose a new examination. Results from validation tests of IPE prove the feasibility of the use of an embedded expert system to capture the art of study comparison. |
