There is unanimous agreement that we are well into the third age of radiology. The first age, from the discovery of the x-ray to approximately World War II, is now legendary. The second age, from World War II to Y2K, the age of the modality, is coming to a close. Be advised that the information age of radiology has begun. Imaging will wither or thrive depending on how well we manage and use the data and information that we are so expert in generating. Nowhere is our progress into this unknown age more evident than in the fact that we are entering Year 4 of the IHE initiative.

In the beginning, there were radiology information systems (RIS) that were used to manage radiology departments and images were managed on film. All agreed this was not good. Decades of research followed by the convergent rise of mass market computing and Internet technologies led to the practicality of PACS. The RIS and the PACS now jabber back and forth between themselves and the hospital information systems (HIS) and clinical information systems (CIS). We understand that RIS and PACS and HIS and CIS and all the other ISes must symbiotically converge to form the elusive electronic patient record. This model, combined with the desire to deploy best of breed computing solutions within a single health care enterprise, can lead to a cacophony of heterogeneous information systems trying to accomplish patient-oriented work-flow tasks. The pendulum then inevitably must swing toward consolidation and integration. There is little need at a single enterprise for 100 or so information systems providing ever smaller marginal functionality to fewer and fewer people, nor is there a single vendor that can provide a single information systems solution for all of the highly complex and specific, patient care work-flow centric tasks that must be coordinated to accomplish the ballet that is medical care. Enter IHE.

IHE is an initiative of the RSNA and the Healthcare Information and Management Systems Society (HIMSS). IHE provides a single sheet of music from which users and vendors can harmoniously reduce the clamor from the heterogeneous information systems at many institutions. The initiative provides a series of venues (committee meetings) that allow users and vendors an opportunity to identify health care processes in need of information systems integration. Planning and technical committees then come up with solutions to accomplish these processes. The committees engineer the solutions using existing health care information standards, currently DICOM and HL-7. The solutions are posed as a series of integration profiles, each of which solves a particular problem. One deliverable from this process is a 302-page technical framework that precisely defines the roles of information system actors in performing transactions to accomplish the integration profiles, and the precise semantics of these transactions. In the late summer, vendors test their implementations at a Connect-a-thon, leading to public demonstrations at the RSNA annual meeting in November and the forthcoming HIMSS meeting. For more about the IHE initiative, go to .

The value of this effort cannot be underestimated. Users can now hope to deploy best-of- breed solutions. Each site can determine which vendor and which information system will play the roles necessary to accomplish a specific task. Vendors win by providing standard interfaces between their information systems and others such that each site becomes a routine installation of a standard interface as opposed to a customized development effort. Everyone benefits from the use of a coherent information model and precise terminology.

In Year 4, IHE will add new integration profiles to those that have already been developed for radiology, as well as develop profiles for laboratory and pharmacy systems. Other medical specialties are being approached. There is an opportunity to coordinate within the IHE initiative many disparate efforts to improve health care information systems with respect to patient safety, service to patients and physicians, research and clinical trials, and human and machine efficiency. Got IHE?