Information relevant to radiological applications is commonly managed by several autonomous medical information systems including hospital information systems (HIS), radiological information systems (RIS), and picture archiving and communications systems (PACS). In this report, we explain the need to coordinate these systems and to provide some framework in which they can exchange information. In the first half of this report, we describe the integration of a PACS system into a hospital operation. Next, we present the interfacing methods between the HIS and the RIS, and between the RIS and the PACS. Two methods are further detailed for the communication between the RIS and the PACS (1) the triggered database to database transfer, and (2) the query protocol. The implementation of the first method successfully allows RIS reports, procedure and patient demographic information to be displayed at the request of the user along with the associated images at a PACS workstation. The query protocol allows a PACS to dynamically query RIS information. It will be eventually integrated into the design of a scientific multimedia distributed medical database system built on top of the HIS, the RIS, and the PACS.