IHE initiative tackles CDs and document sharing

The Integrating the Healthcare Enterprise initiative continued throughout 2004 to round out its blueprint for designing interoperable systems and products, creating new supplements and integration profiles. Radiology-centric portable data, nuclear medicine profiles, and several additions to the scheduled workflow profile topped the list. The IHE also tackled the electronic health record with the introduction of the cross-enterprise document-sharing integration profile.

The portable data for imaging profile, or PDI, was demonstrated alongside user success stories at the 2004 RSNA meeting. The profile addresses the increasingly popular practice of placing images onto CDs for patients and targets the subsequent problem of incompatible media readers.

"This profile solves a very tricky problem that we've created for ourselves," said Dr. David Channin, chief of imaging informatics at Northwestern University. "Now that institutions have PACS, they can easily make CDs for images."

The plethora of imaging CDs in circulation can cause headaches for radiologists. If a patient has CD images created at the Mayo Clinic, for example, and then brings them to Northwestern, the radiologists there may have trouble comparing those images with any previous images the patient may have had at Northwestern or with new imaging studies created at the second institution. They often have to find a PC image viewer, pull up the images, and then run over to the PACS to view relevant priors from their own institution, Channin said.

Specifications in the integration profile include CD file naming conventions that apply to all files on the CD, DICOMDIR requirements, and specifications for media readers, importers, and identifiers. The profile facilitates data retrieval reliability by removing common sources of error and adding a testing process. It also supports Web data, enabling image viewing on a Web browser, and provides import cleanup requirements such as the ability to fix patient IDs.

"Using the profile, we can now put an outside historical CT exam into the RIS, where the data can then go to a workstation that supports PDI," Channin said. "We can then query that work list for an accession number, and it will reconcile any information in the DICOM headers to import the image correctly and store the study into our PACS. For that patient, we'll be able to see the current study in our system and display our historical images next to the outside images."

NUCLEAR KNOW-HOW

The rising popularity of nuclear medicine imaging has spurred several organizations to develop DICOM standards for seamless transmission of these complex dynamic images in the digital world of PACS. The Society of Nuclear Medicine DICOM working group and the IHE have jointly developed a nuclear medicine image profile.

The profile has two major parts, said working group chair Dr. Jerold W. Wallis, an associate professor of radiology at the Mallinckrodt Institute of Radiology. One involves educating PACS designers about the unique qualities of nuclear medicine image data to facilitate development of systems that can handle complex multiframe images. Those images are sometimes acquired from different heads of the gamma camera or different energy windows as part of a multi-isotope study.

The second part of the profile outlines specific IHE compliance requirements for vendors. They include the ability to adjust upper and lower levels of gray-scale window settings, show several cine images simultaneously, and use customized logic to avoid showing postage-stamp-sized images.

Trial implementation of the profile began last summer. Participating vendors will add nuclear medicine features to an in-house version of their software. Vendors could bring their systems to an IHE connect-a-thon in January for testing and validation.

"The number of participating vendors and the priority they give to this effort depend on consumer demand. It is up to the nuclear medicine community to ask vendors for the profile in order to push the process forward," Wallis said.

SMOOTHING WORKFLOW

Several updates to the scheduled workflow profile were unveiled at the 2004 RSNA meeting. The IHE initiative also released a departmental workflow white paper that outlines an overall model covering all important workflow management issues within an imaging department.

The new appointment notification option allows for the transmission of scheduled appointment dates and times from the radiology department to an order placer actor. The instance availability notification option informs workflow managers of the availability status of diagnostic objects. The option is available to all workflow management actors, allowing them to display availability of input data and update work list items based on data availability.

"There were five different vendors at RSNA doing a complete radiology workflow," Channin said. "It was very successful, with more than 1300 people going through the exhibit."

BLUEPRINT FOR DOCUMENT SHARING

The IT arm of the initiative has moved into the realm of the electronic health record with its cross-enterprise document sharing (XDS) integration profile. The profile will be put to the test at an interoperability showcase at the Health Information and Management Systems Society's 2005 conference this month. It enables document linkage and information sharing across hospital, outpatient, and other care settings.

To solve interoperability problems, the IHE often mixes healthcare IT and other standards. The need to look beyond healthcare is the prime reason the initiative is independent from any specific standards development organization, although it cooperates with them as a customer of their standards, according to Charles Parisot, a member of IHE national committees in the U.S. and Europe, and IHE IT infrastructure technical committee cochair.

The XDS profile, which was set to share a single health record between 17 electronic medical records systems from different vendors at the HIMSS conference, is based on a combination of e-commerce standards and healthcare-specific standards.

"The 20,000 attendees of the HIMSS exhibition should be the first to experience this breakthrough in interoperability to improve the way their systems interoperate nationwide. IHE serves interoperability needs not only within healthcare enterprises but also between them," Parisot said.