The case for RIS/PACS integration

Abstract

Why integrate PACS with the RIS? To improve workflow, of course, but what workflow? Much of the focus is on improving the flow of images for the radiologist, which is certainly a good thing to do, but what about the rest of the order process? Typical PACS system architecture begins with the HIS since this is where the correct patient demographic information and in many cases the orders originate. Correct patient and order information is sent from the HIS to the RIS using HL7 commands for Admission/Discharge/Transfer (ADT) and Order/Entry. HL7 is the communications protocol used in virtually all information systems. For the first step in communicating with PACS, patient and order information from the RIS is sent to a device called a PACS broker. This is necessary because most PACS systems do not support HL7 directly, and a translation is required. Images from each imaging modality are also sent to the broker using the DICOM standard. If an imaging modality does not support DICOM, then an additional box is used to convert the images to a DICOM file. The broker then sends completed DICOM files to the PACS for storage, distribution and viewing. That approach has worked well for the first stage of PACS utilization. However, experienced PACS users have identified the need to improve workflow, and many feel that closer communication with the RIS will solve many of the current limitations. This approach is sometimes called a "brokerless" solution but is probably better described as incorporating broker functions into the RIS. There are several potential advantages of incorporating the broker functions into the RIS: Access to all RIS information on patients, orders and results is available and can be used in many ways to improve workflow. Supporting all DICOM services directly from the RIS ensures that the latest and most complete information is always used. For example, DICOM Modality Worklists can be provided directly from the RIS, which guarantees that they are updated immediately. The RIS can manage the complete order workflow, not just images. License, implementation and support costs can be reduced by eliminating HL7 interfaces to an external broker. Managing workflow is the key to improved productivity and patient care from PACS. However, coordinated management of order workflow from the RIS and image workflow from the PACS is required to get the full benefit. The RIS has immediate and broad access to patient and order information. As a result, it is the natural place to take the lead in managing this coordinated workflow. While many older RIS and PACS systems are not yet capable of some of the integration features described above, several new systems are moving rapidly in that direction.