Radiologists were the first physicians to embrace picture archiving systems because radiology workflow is based on image management and interpretation. However, other areas of medicine are increasingly relying on image data to supplement traditional patient information. Examples can be found in virtually every department, including images of skin lesions in dermatology, retinal pictures in ophthalmology, endoscopic images in gastroenterology and otolaryngology, and gross and microscopic specimens in pathology. Such nonradiologic medical images are generally grouped together under the term “visible light images.”
|Barton F. Branstetter IV, MD|
Although it would be possible to create a separate information system to manage the images in each medical specialty, it is inviting to suggest that we could employ the resources developed for radiology throughout these other areas. The established benefits of PACS (rapid creation and distribution of reports, image availability, and, ultimately, improved patient care) could then be extended from radiologic images to visible light images. Creating a new information system in each specialty incurs additional expenses, requires additional ongoing support, and prevents a unified interface for the image consumers: most often, referring physicians.
In addition to patient care and physician efficiency, financial considerations play a role in the incorporation of visible light images. Some medical enterprises consider PACS to be a cost specific to the radiology department, while other hospitals consider image distribution to be a system-wide concern, so that funding comes from a higher administrative level. If the radiology department is responsible for the cost of PACS, then incorporation of visible light objects has the potential to minimize costs by charging operational costs back to the department that is storing images. This can help to defray the overall cost of PACS to radiology. If the PACS is supported at a hospital level, the hospital will want to leverage the investment for maximum gain. Shared resources for image distribution can reduce overall operational costs. Volume discounts may also be achieved with certain PACS pricing models. In cases where a hospital system is still in a film environment, the ability to use PACS for image distribution outside of radiology can be used to fiscally justify an initial PACS acquisition. Another benefit of shared resources is reduced information technology (IT) support; if all departments are using a single PACS for both radiology and visible light images, fewer IT support personnel are needed to maintain the system.
For hospital systems with a complete electronic medical record (EMR), a combined image archive is easier to incorporate than several distributed systems. It also reduces the need for interface development within the EMR.
THE UNIVERSITY OF PITTSBURGH FIX
|Figure 1. SimpleDICOM Wrapper as data is being added. (Click the image for a larger version.)|
At the University of Pittsburgh, we have developed software that allows visible light images to be encapsulated within a DICOM object. Metadata such as patient identifiers and dates are placed in a DICOM header, and the object can then be incorporated into the PACS. Once the images have been incorporated, they are distributed just as radiologic images are. This allows other departments to leverage the robust distribution system that has been established for radiology. Primary care physicians have access to images (and, sometimes more important, associated reports) from consulting physicians in a variety of specialties.
SimpleDICOM Wrapper is deployed within clinics to ensure point-of-presence usability. This is an important aspect of the software—if clinicians are not able to immediately incorporate images during the normal workflow of patient care, the images are likely to slip through the cracks and never make it to the PACS.
The pertinent metadata for an examination vary dramatically from one department to another. Whereas dermatologists need full-body mapping to identify where a lesion is located, ophthalmologists need a retinal map. Thus, considerable software development was needed for each department in which SimpleDICOM Wrapper is deployed. This process began with surveys of the clinical personnel (both physicians and support personnel) to ensure that the software met the specific needs of that department. Representatives from the clinical department remained closely involved throughout the development process to ensure that the interface envisioned by the programming team is the same as that envisioned by the users. The lessons learned from the early days of PACS, when there was insufficient radiologist input, should be remembered when extending technology to the rest of the enterprise—input from the final users is critical throughout development.
One of the major benefits of the system is that primary care physicians have a single system from which to access patient images. If images are scattered among departmental archiving systems, consumers are less likely to be trained in the use of all systems and less likely to maintain regular access. Some hospitals attempt to overcome this problem with centralized portals to various information systems, but a single information system is less prone to error and easier for the users.
SHOULD WE WAIT?
It is clear that one of the long-term goals of imaging informatics should be to establish standards by which DICOM-compliant nonradiologic imaging modalities can supply images directly to any PACS in a consumable format. Unfortunately, the development of standards is (by necessity) a long process. Agreement must be reached not only within the radiologist and informatician communities, but also with the vendors, both on the PACS side and on the modality side. Even once standards are in place, it may take many years before the formats are ubiquitous in new equipment. Older equipment may or may not be capable of upgrade to newer standards.
|Figure 2. Dermatological images after they are incorporated into the PACS. (Click the image for a larger version.)|
With this in mind, we felt that an immediate solution was needed to allow radiology departments to take advantage of the potential workflow and financial advantages of incorporating visible light images into the PACS. A key element of such a system is vendor independence. The software must be capable of receiving input from virtually any visible light system (including digital cameras) and communicating with virtually any PACS. Another key element is usability: after initial setup and training, even non-computer-savvy users should be able to send images to the PACS. Customizability is also critical. We cannot expect that dermatologists and ophthalmologists have the same needs when defining metadata on their images. The more robust the system for archiving metadata, the more clinically useful the system will be, and the more likely other departments will be interested in collaborating for image storage.
These key elements are critical to the success of a visible light incorporation system, but they are not generally under the purview of a standards committee. In other words, standards are a necessary and laudable goal, but they do not form a complete picture. Interface and usability issues are at least as important. These issues can be addressed now, before the standards are universally available.
NOTE: The University of Pittsburgh Medical Center has made the SimpleDICOM Wrapper available as freeware at: www.radiology.upmc.edu/Public/public_resources/software/SimpleDICOM .
Barton F. Branstetter IV, MD, is associate director of radiology informatics, University of Pittsburgh Medical Center.