Government efforts to improve health care via information technology have increasingly focused on picture archiving and communications systems (PACS), which unite medical imaging devices with electronic storage and networks.

In the most noteworthy example, the Defense and Veterans Affairs departments are working on a multifaceted project to share digital radiology imagery. Their work has taken on a new urgency in the wake of recent revelations about the lack of integration between medical centers that treat wounded soldiers.

Digital medical imaging is also big business. According to a report published in May by Datamonitor, a market research firm based in London, the PACS market in Europe and North America will nearly double to $8.6 billion by 2010.

Datamonitor noted a significant shift from PACS' traditional focus on radiology to medical imaging used in cardiology, pathology and dermatology. Such systems can also nearly eliminate the mishandling of film, which currently results in a 5 percent to 20 percent image loss rate, while enabling much quicker turnarounds for patients.

Steady advances in IT bandwidth, storage capacity and performance have reduced PACS' prices, making them more affordable for more hospitals.

"The cost of storage is coming down all the time, but the amount being stored is going up," said Justin Davidson, the Datamonitor associate analyst who wrote the report.

PACS software is also getting cheaper because new component solutions allow incremental upgrades.

"If there are affordability issues, it's always going to start with radiology," Davidson said. "That's where the biggest benefits are."

After radiology, providers typically add other imaging capabilities and services, such as more viewing stations at facilities, Web access from physicians' homes and other remote locations, or nondiagnostic imagery on wireless computers at patients' bedsides, Davidson said.

Beyond lower costs, changes in reimbursements have also driven demand for the technology. "Radiologists had their reimbursements cut dramatically over the years," said Kay Jex, a vice president at NovaRad, a PACS vendor. "That hurt hospitals in a lot of ways because that's where they make their money."

In response, providers have consolidated their radiology imaging, sometimes even opening freestanding imaging centers, Jex said.

Clearer pictures
Like many specialized technologies, PACS have evolved in recent decades from closed, proprietary systems to networked ones that use open standards. The broader trend toward Internet technologies has also affected PACS - behind the scenes as vendors rebuild systems on Web services architectures and upfront in easier-to-use screen interfaces that run on Web browsers.

"Each patient's master folder has a URL linked to it, and each image can have a URL," said Matt Meitzner, senior associate in the Applied Solutions Group at the ECRI Institute, a nonprofit consulting group.

Further out on the Web's leading edge, some PACS can now display
3-D images that formerly required expensive graphics workstations.

However, advances in storage have completely altered the performance and affordability of PACS. Before fast hard drives became so cheap, PACS made do with a variety of mechanisms, including optical disks and tape drives that required complicated schemes to guarantee that access speeds would not compromise care.

But with the recent advances in hard drives' magnetic technology, "you can have one server with three hard drives and have almost 3 terabytes of storage," Meitzner said. "You don't need to have these multiple tiers."

Cheaper high-capacity storage and networks have also improved backup and recovery of medical images and data. This fall, Philips Radiology Informatics will provide a backup storage and recovery infrastructure for minimal cost at centralized disaster recovery centers at VA hospita
ls that use iSite, the company's PACS system.

Previously, the facilities' employees made manual copies and sent them off-site. Now, using Philips' iVault technology, the images will be available within 96 hours.

"The responsibility to restore the system is all on us," said Greg Masek, Philips' senior director of customer operations.

PACS experts say the Digital Imaging and Communications in Medicine standard provides a solid support for the industry. DICOM can handle diverse types of radiology images and storage formats, and it allows digital devices to communicate with one another.

"DICOM is…kind of a gold standard," Meitzner said. "I don't get the impression there's a lot more work to be done."

A key component of DICOM is worklist management, which enables radiologists' reports to be reliably attached to images, eliminating transcription error rates that can reach 20 percent, Meitzner said. The worklist feature also eases integration between PACS and hospitals' radiology information systems (RIS), which facilities typically use to schedule radiology appointments and inform the staff when results are ready.

Two other standards further bolster the overall integration picture: Health Level 7 (HL7) for electronic health records and the Integrated Healthcare Enterprise (IHE), an effort to improve workflows and other types of communication among DICOM, HL7 and other standards. Some PACS vendors are beginning to adopt IHE, several sources said.

PACS economics
Besides improving patient care and business efficiency, analysts say PACS can show a return on investment in less than a year, largely because of savings in film costs as providers switch to digital imaging.

Network PACS open opportunities to share images with facilities regardless of how far away they are, which can bring digital radiology to hospitals and clinics that are too small to afford their own.

"They don't have a lot of money they can put down upfront," Jex said. "That hospital needs everything that a large hospital needs, it just needs a smaller archive."

NovaRad meets the needs of small community hospitals by charging for installation and training upfront. Afterward, hospitals pay a monthly fee that stays fixed during a typical three-to-five-year contract, Jex said.

Further cost savings come from having the vendor host the PACS or its storage archives off-site rather than buying all the hardware, though some hospitals like the security of keeping the records. An intermediate step is to lease equipment from the PACS vendor. Meitzner said that because vendors make little money on hardware, many of them will allow hospitals with well-staffed IT departments to install the company's software on their own servers and storage devices.

Health care providers can also take half steps toward a full-fledged PACS, such as using DICOM to connect black boxes to older devices or PACS. However, such approaches do not provide all of DICOM's features, Meitzner said. Printer converters, for example, can drop data, providing "essentially a screen capture that you can play with," he said.

Other vendors make boxes that act like brokers between devices and systems, and many PACS and RIS vendors are incorporating that feature into their systems.

"Now more PACS speak HL7, and more RIS speak DICOM," Meitzner said.

Essex is a freelance technology writer based in Antrim, N.H.