Vendors experiment with approach to PACS/IT interfaces

March 6, 2006

PACS must bridge the gap between radiology and the rest of medicine if it is to remain a relevant part of medical practice. The Integrating the Healthcare Enterprise initiative wants to lend a hand.

PACS must bridge the gap between radiology and the rest of medicine if it is to remain a relevant part of medical practice. The Integrating the Healthcare Enterprise initiative wants to lend a hand.

The IHE is promoting XDS (Cross-enterprise Document Sharing) as a standards-based means for sharing data across different IT systems. At the Healthcare Information and Management Systems Society conference, Feb. 12 to 16 in San Diego, the IHE demonstrated how the imaging component, called XDS-I, can be used to share medical images across an enterprise, while maintaining radiology control over them.

In this approach, the images stay put in archives managed by radiology. Other disciplines gain access to them by following "pointers" residing on a registry or index of the images. This registry is built using XDS, which appeared only last year ago as a technical framework within the IHE.

"This year we have seen more robustness and specialization in terms of this interoperability being built into products," said John Donnelly, president of IntePro Solutions, a consulting firm in Colonia, NJ, that helps hospitals implement IT systems.

At the HIMSS conference, the IHE staged an Interoperability Showcase simulating an electronic health record spanning a regional health information organization (RHIO). The case, used as an example, involved a patient whose chest radiograph was acquired at one hospital and later retrieved at another. Ten different IT systems made by 10 different vendors were involved in the demonstration. XDS connected IT systems in and outside of radiology.

Patient demographics and the order for a chest radiograph, input using CPSI's ChartLink Computerized Physician Order Entry, were transferred to a Cerner radiology information system, which created a work list item. The order was then reviewed and routed to the Kodak DirectView DR, which specializes in digital radiography. When the radiograph was completed, the DirectView DR notified the Cerner RIS, then transmitted patient data along with the images to a GE Centricity PACS, which confirmed storage and notified the DR modality to delete the images from local storage. It also notified the RIS and reporting system that the images were available for review.

Pulmonary nodules were quantified and the images annotated using a review station linked to an Infinitt PACS. The postprocessed images were then transferred to the Centricity PACS, which created a manifest of images and published them in the IBM Document Repository. The IBM system then registered these documents using HXTI's iHistory, vendor-neutral software that creates a registry of patient information.

Centricity used the Initiate Identity Hub to map its local patient identifier to the RHIO. This software sorted the relevant information from duplicate and fragmented records, linking them together and across the various data sources.

The demonstration, which took about 30 minutes, culminated in a simulated visit to the emergency room of a second hospital, represented by a pod in the IHE booth. There a Centricity RIS retrieved the chest images of the patient from the RHIO. Unfortunately, the result fell short of expectations.

The images retrieved were the unprocessed radiographs, not the ones postprocessed to include the nodule measurements. The retrieval went awry because a pointer was aimed in the wrong direction, according to Donnelly.

"There are a lot of little things going on behind the scenes that don't come out until you really start testing them," he said.

Vendors obviously are still working out the bugs in their XDS-based technologies. They most recently used a "connect-a-thon" to test improvements. This connect-a-thon, held in January at the RSNA headquarters and involving dozens of IT vendors, provided corporate R&D a chance to see whether their systems work with those of other vendors.

"The vendors can develop their product conformance statements, which makes it easier to integrate products," said Michael Glickman, president of Computer Networks Architects, a Rockville, MD, company specializing in system integration networking and telecommunication services.

A lot of effort at the January event went into XDS-based products. Some of these products could make their first appearance at next year's RSNA meeting, said Chris Carr, RSNA director of informatics. But they probably won't be featured too prominently.

"This is not the kind of thing that will catch the eye of a radiologist, at least not the way a fancy image-processing algorithm or 3D processing system does," he said.

XDS will gain the respect it deserves only if radiologists appreciate the need to share information among other specialties. One way to sensitize radiologists to this need is by drawing attention to their own needs for a patient's previous imaging history. Without this history, radiologists may call for tests that wouldn't be necessary if the results obtained recently at another institution could be retrieved.

"They know that is a problem and they are concerned with making their service as good as it can be to give the best quality of care they can," Carr said.