Introducing a digital modality to any previously all-analog radiology environment invariably represents a giant leap forward in that enterprise’sdigital journey-provided, of course, that the addition of such equipment is accompanied by installation of some means of viewing the electronically acquired images.

One option is to use a picture archiving and communications system (PACS) to generate soft copy at a workstation. For many radiology departments and outpatient imaging centers, however, a PACS may not be immediately financiall feasible. Thus, an alternative strategy would be to employ an imager to print the digital signal onto film.

Ray Russell, director of hard-copy imaging systems for Agfa, is based in Greenville, SC. He says, “Imagers are probably the best choice for an enterprise converting to digital modalities but lacking the wherewithal to support a full PACS deployment of workstations, archives, servers, and broadband networking infrastructure.”

Imagers can prove equally indispensable to the enterprise that is actually quite far along on its journey to filmlessness. No finer illustration of this point exists than Florida Hospital, a seven-institution health care delivery system headquartered in Orlando and having a combined total of 1,776 beds.

Sally Grady, RT

For more than a decade, Florida Hospital has aggressively pursued development of a fully electronic environment. A PACS is currently installed at each of its facilities, with the modalities of CT, MRI, ultrasound, and nuclear medicine completely networked at most of them. Sally Grady, RT, imaging center director for two Florida Hospital sites, says, “We have so much traffic on our network that we recently installed two superservers to accommodate it all.” Grady is responsible for imaging at one site in the Walt Disney World? model community of Celebration; the other site is in the nearby city of Kissimmee. “Aided by this capability, we plan to take Florida Hospital Kissimmee filmless by year’s end. Most of the emergency departments at our seven sites will be filmless by the close of 2001. Florida Hospital Celebration, which opened in 1998, was virtually filmless from the start.”

Still, a substantial portion of this year’s expected 750,000 radiology examinations at Florida Hospital will be printed, even at Florida Hospital Celebration, where up to 25% of the studies are likely to have hard-copy output. “We print film mainly for the benefit of referring physicians,” Grady explains. “Orthopedic surgeons are the ones who most like to see patient images on film, but we also print film for the benefit of the patients themselves. About 70% of the patients coming through our emergency department at Florida Hospital Celebration are Disney World visitors. It makes no difference if the study came out negative; a lot of them simply want hard copy to keep as a souvenir.”

Decentralized Imagers

Florida Hospital has deployed 22 imagers enterprise wide. Of these, eight are older, wet-technology devices. The remainder are the newer dry variety (see sidebar). “We found that, in addition to giving us a way to make hard copies, distributed imagers increased the efficiency of our operations and contributed to a reduction in costs,” Grady says.

A prime benefit of imagers (particularly dry imagers, which are considerably smaller and less costly than their wet counterparts) is the ability of an institution to install them near the equipment capturing the images. Typically, the imager is placed in the same room as the imaging modality, according to Russell. “The technologist who operates the modality is usually the same person who also operates the imager,” he says. “Because the imager is right there in the room, the technologist never has to leave the patient unattended. The technologist simply presses the print button on the imager console. A minute later, the film pops out, the technologist reviews the study for quality, and sends the patient on his or her way. It’s very quick.”

In the days before dry technology, radiology enterprises that acquired imagers often installed them in centralized areas, such as in the same darkrooms where analog films were processed. This kind of deployment made sense in light of the need to have special plumbing for wet imagers in order to dispose of spent chemicals safely, Russell notes. It also made sense because facilities on tight budgets could not afford to buy more than one or two wet imagers at a time.

“Centralized deployment allowed the greatest number of users to have? access to the handful of imagers a radiology department was likely to be able to cost justify,” Russell says. “The drawback, of course, was that users had to leave the room where the modality and the patient were located in order to seek out this central processing area. In addition to the problem of leaving the patient alone, there was also the time-consuming aspect of having to walk a long way to reach the centralized imager.”

Dry imagers require no plumbing. Coupled with their smaller size and price, that characteristic has encouraged radiology enterprises to buy them in larger quantities and adopt a decentralized approach to deployment. With decentralization, imaging throughput and productivity were able to rise sharply. “Eliminating the time spent walking the corridors meant technologists could perform more studies each day,” Russell says.

That certainly corresponds to Grady’s experience. She reports that she started the Celebration facility with just a pair of imagers and placed them in a central area of the second-floor radiology department. This arrangement worked for images produced within the confines of the department, but not for those produced in the first-floor emergency department. “It’s a very far distance between the emergency department and radiology, which meant that my technologists had to keep running back and forth quite a bit,” she says. “The solution was to take one of those imagers and relocate it in the emergency department. We got a huge productivity boost out of that.”

Ed Majors, RT

Helpful, too, in increasing productivity was the ease of use inherent in the employment of dry imagers. “Loading and unloading film are nothing like the processes involved in working with an analog x-ray machine,” Russell says. “For example, there’s no putting a cassette in a pass box; there’s no having a darkroom technologist unload the film, put it in a processor, reload the cassette, and put it back in the pass box before going out to do another examination. Consequently, there’s no risk of producing double exposures or of having other kinds of errors resulting from trying to reload a cassette while fumbling around in a low-light environment like the darkroom.”

According to Russell, the elimination of darkroom errors-along with the elimination of the need for chemicals and a darkroom technologist-can save a radiology enterprise 10% to 15% of the cost of film-related expenses. Those saving, however, are somewhat offset by the capital cost of the equipment. Depending on how the capital acquisition is amortized, the net savings could be less than 10% to 15%, Russell notes.

Beyond saving costs, imagers can also save the day, as they did for Florida Hospital with regard to staffing concerns. Ed Majors, RT is director of special imaging at Florida Hospital Orlando. He says, “One of our biggest challenges has been recruiting and retaining good people. We’re constantly dealing with staff shortages across every modality, in the same way as virtually every other hospital system in the United States these days. Imagers have helped by freeing technologists’ time and, thus, allowing us to restructure their work assignments. In so doing, we’ve lessened the pressure we were under to hire more people.”

Understanding Imager Technology

Imagers fall into two categories: the wet type and the dry type. An imager is deemed wet if it uses a chemical bath to produce an image and dry if it does not.

Both wet and dry imagers are computer driven and almost always employ thermal heat to inscribe, onto a sheet of film, the images acquired from a digital modality, be it computed radiography, digital radiography, CT, MRI, nuclear medicine, ultrasound, or positron-emission tomography.

Ray Russell, Greenville, SC–based director of hard-copy imaging systems for Agfa, explains, “In a wet imager, laser produce heat that exposes the film, which then enters a processor chamber that contains developer, fixer, and wash. Processing takes about one minute. In a dry imager, heat again is used to expose the film, but the heat takes the place of chemicals to fix that image on the film. Agfa’s dry imagers use heat not only to fix the image but to imprint it on the film. We call this the contact thermal method.”

Russell notes that Agfa wet imagers can be used as both printers for digital output and as darkroom processors for analog film. “This is an advantageous feature for departments that have a mix of digital and analog modalities,” he says. “It can make more economic sense to buy one of these wet imagers than to maintain darkroom equipment for the analog modalities and then a dry imager for the digital ones.”

Wet imagers employ, as their print medium, a standard sheet of silver-halide-grained film similar to that used in photography. In dry imagers, the medium is a sheet of polyester-based film. “Systems employing light-sensitive films require use of a special tray to allow unexposed films to be loaded into the imager if the user plans not to darken the room first,” Russell says. “Heat-sensitive films can be loaded without any special precautions in a brightly illuminated room.”

Russell reports that the imager market is dominated today by dry-technology systems. “Last year, 95% of all imagers sold in the United States were of the dry type,” he says. “The wet imager was the original type of technology when imagers first arrived on the scene more than a decade ago. Gradually, its hold on the market slipped as dry technology proved itself more economical.”

In addition, it is more environmentally friendly. “Since dry systems use no chemicals, you don’t need to worry about how you will safely dispose of spent fixer and the like,” Russell says. As for consumables costs, dry imager media tends to be the more expensive. Overall, however, dry imagers are seen as more cost efficient. In terms of ability to produce a clinically satisfactory diagnostic image, there is no real difference between wet and dry imagers, Russell states. “We are, nonetheless, working on ways to improve resolution,” he adds. “We believe our contact thermal technology provides a strong foundation for achieving these higher resolutions. Already, we’ve received Food and Drug Administration clearance for our DryStar 450, a contact thermal system having 508 dots per inch. That’s only the beginning, as we see it.”

Justifying Imagers

Florida Hospital acquired its first wet imager in 1989. It chose Agfa as the vendor because the company’s imagers offered the smallest footprint of any on the market at that time. “Space was at a premium for us in our then-existing facilities,” Majors says. More imagers were obtained from Agfa over the years that followed. “It is a good product; we decided to stick with it,” Majors states.

Grady says that no one with budget-approval power had to be convinced to let the radiology department buy imagers. “It wasn’t necessary for us to develop an imager acquisition plan,” she reports. “In an enterprise of our size, imagers are not seen by financial decision makers in the same way they would see a piece of capital equipment like a new digital modality. Imagers are comparatively modestly priced. They’re also recognized as must-have items; everyone understands the importance of an imager.”

Installation of the imagers bought during Florida Hospital’s first round of acquisitions was also reasonably easy. It became more so with later purchases. “The technology kept getting better and better,” Grady says. “Now, all you need to provide is an electrical outlet and a data jack. It’s pretty much plug and play.”

There was one installation, however, that caused Grady some jitters because it went less smoothly. It happened earlier this year as Florida Hospital’s Celebration facility prepared to introduce digital mammography. Grady says, “We were putting in a wet imager. It was wet because that’s the only kind the Food and Drug Administration (FDA) has approved for use in digital mammography. There are only two makers of this particular type of FDA-approved wet imager, with Agfa being one of them. There were a lot of little things that kept going wrong; for example, the chemical vendor’s technician did not have the right tubing available for the wet processor. These missteps prevented me from producing test studies for FDA review in keeping with our timetable, so the debut of our digital mammography service was delayed a bit. It would have been delayed longer, had it not been for the way Agfa’s representative went way beyond the call of duty to get these problems ironed out.”

Commitment to vendor standardization was a factor in Florida Hospital’s decision to select Agfa’s digital-mammography-approved imager. Equally important, though, was the Agfa product’s ability to produce up to 90 digital mammography films per hour, compared to the 20 films per hour of the competing brand’s offering, Grady reports. “We’ve been told that Agfa is developing a dry imager for digital mammography, and it appears to be on its way to FDA approval,” she says. “Assuming the FDA clears it, the product should hit market late this year, at the earliest. When it does arrive, we plan to replace the wet imager with a new dry one.”

Dry imagers are relatively new to Florida Hospital. The first one was installed in 1997. “We did a study afterward to compare the performance of our wet imagers with that of the dry imager,” Majors says. “We found that the dry imager was more economical than the wet imagers. Since that study, we’ve acquired dry imagers almost exclusively. Eventually, we’d like to have dry imagers only.”

Majors expects that imagers, dry and wet, will continue to be a crucial tool for Florida Hospital’s radiology enterprise well into the future. He says the same will hold true for just about every other radiology department or imaging center in the United States. “The need to make hard-copy images won’t be going away anytime soon, no matter how close to having a fully digital environment an enterprise comes,” he says. “You’re going to have referring physicians for many years who are only going to be comfortable if you give them a piece of film to look at; these physicians are accustomed to being able to grab the film, quickly glance at it, show it to the patient if need be, have a discussion with the patient, and then move on to the next case. For them, this is the fastest and most productive way to deal with images.”?

Rich Smith is a contributing writer for Decisions in Axis Imaging News.