The power of PACS is undeniable, but it’s not the only communication tool that’s changing the structure of the radiology business. Teleradiology adds another layer to the HIS/RIS/PACS hierarchy and is profoundly impacting the nature and speed of image sharing by acting as a virtual courier, transferring images around the world.

This communication breakthrough allows users to communicate information in PACS to those outside the network by electronically transmitting both the images and the consultative text to a variety of users, including referring physicians, consultants, affiliated hospitals, and practitioners’ home offices. And all of it can be done without hefty FedEx and courier bills.

Not surprisingly, practitioners from a range of specialties beyond radiologists and radiology technologists are finding ways to implement the efficiencies of this digital revolution. Ambulatory surgery centers, independent imaging centers, and orthopedic groups also are adopting such systems.

Getting Connected
Teleradiology can add a functional layer to PACS—and indeed is incorporated on some level or another in almost every PACS. But also, teleradiology is quite capable of holding its own. Still, many healthcare executives mistakenly believe that if they use teleradiology, they’re using PACS; however, teleradiology is an output method, not a linking system. PACS is not a required element for teleradiology, which also can be purchased as a stand-alone system.

AMICAS’ LightView powers Personal AMICAS for push/pull Web-based teleradiology.

“Typically, teleradiology is the initial entrée for many institutions to get into PACS,” says Brad Levin, director of strategic marketing for AMICAS Inc (Boston). “Once [institutions] provide these services, they frequently upgrade their systems to full PACS.”

Also, teleradiology is a valuable tool for many smaller organizations that don’t yet have the volume to justify the capital expenditure to acquire PACS. “You put in a Web-based teleradiology server, and you’ve taken your first step toward PACS,” agrees Kobi Margolin, VP of Algotec (Duluth, Ga), an Eastman Kodak company. The implementation can be done in baby steps.

The Kodak DirectView Web Distribution System can be used for both teleradiology and Web-based image distribution to referring physicians. It also forms the foundation for a full Kodak DirectView PACS System 5 implementation.

First, the most basic stand-alone teleradiology system—available for less than $100,000—requires only teleradiology software and a Web server. Most physicians have a PC and an Internet connection for plugging in to the system. The next step is adding storage and archiving architecture. The final addition is a high-end workstation for primary reading.

Choosing a teleradiology system can be a daunting task; the goal is speed, and any kinks in the system undermine that aim. As company reps tout their own products and services, it’s important to understand which elements of a package differentiate one teleradiology provider from another.

“Some vendors will lead you to believe that they have magic beans that will make all the implementation issues magically disappear,” says Joe Mulvihill, director of marketing and strategic alliances at BRIT Systems (Dallas). “There are no magic beans. No magic hardware will make electrons move faster through one vendor’s network line than another’s. No magic compression algorithm will drastically reduce the image data set size without losing the original image detail.

“Everyone is using the same general types of hardware and compression algorithms, with everyone being required to obey the same laws of physics,” he continues. “The differences between the vendors are the specific methods they use to bring all of these items into a useable solution.”

A Brief History
Teleradiology has made impressive strides since its “camera-on-a-stick” days, when radiology techs simply put film on a light box, did a frame grab with a digital camera, and transmitted the image to an end user. The process was strangled by limitations: the

resolution of the camera, where noise was added to the image; transmission over telephone lines, where details were lost; and the use of analog phone lines, which compounded that loss.

Sound like ancient history? This process proliferated as recently as the late 1980s and early 1990s—and, while uncommon, it’s still sometimes used today, according to John Romlein, MSE, VP of the eastern region at Xtria Healthcare (Dallas). “As long as it works, they’ll still use it,” he admits.

More popular today, though, is a teleradiology system that’s integrated with PACS, giving users more bang for their buck with improved quality and efficiency.

Teleradiology’s popularity can be attributed, in part, to its own transformation. As recently as the late 1990s, teleradiology required a dedicated “send station” and at least one dedicated “receive station.” Even when technology evolved and allowed the “receive station” to be a laptop computer for improved portability, the system was unwieldy and cost prohibitive.

Enter Web-based image management. “[A user’s] home PC became the teleradiology ‘receive station’ by virtue of the connection that [the user] had to the Web server,” explains Algotec’s Margolin. “Around 1996, we came up with a different model for teleradiology. It used the power of the Internet to move around images. We could provide you with a Web server, which became the epicenter for images that could have been acquired in many different locations, and it made those images accessible from many different locations.”

With Web-based systems, the dedicated send and receive stations were replaced by a Web server. And with standardization of PACS and DICOM, teleradiology became more affordable and accessible.

“You want teleradiology to present the same information that your system has,” says Xtria’s Romlein. The images themselves are DICOM accessible, and the informational files that accompany the images need to be as well. “Database entries can be transported only by a system that can read that information from the database.”

AMICAS’ Levin adds, “PACS are used for the primary interpretation of diagnostic imaging studies and are archived in some kind of digital capacity, eliminating or reducing the production of film. With teleradiology, hospitals and imaging centers can send those digital images to a destination workstation at the other end. They can get an on-call opinion over the phone or through a dictation system.”

Images On Call
Overworked radiologists haven’t missed a beat in embracing a system that buys them more sleep during the nights they’re on call. Instead of being summoned to a hospital in the middle of the night to review films, radiologists can access images sent to their home computers.

“It’s very often a rule-out situation,” Romlein says. Emergency evaluations usually fall into the gross abnormality category, making the images simple to evaluate even without sophisticated hardware. That’s important for radiologists without state-of-the-art home computer systems.

“Teleradiology represents a paradigm shift in the way the institution deals with workflow,” Levin says. “They can access images digitally—anywhere—without having to print. It’s like coming from the Stone Age into the modern era.”

And it’s happening at warp speed. PACS have been in play for about 15 years, and teleradiology for about 4 years; yet, many organizations can’t imagine working without either system.

“It’s much more attainable than it’s ever been,” Levin says. “The smartest institutions are those that have an upgrade capability with their systems.”

For example, AMICAS’ products have what Levin calls “incremental adoption” capability, meaning customers can purchase a system that services their current needs and remain confident that they don’t have to scrap the system if they decide to add functionality down the line. The upgrades will work with the older systems that the customers have purchased.

The system works virtually the same for every size of institution, and the cost is assessed based upon licenses. The capabilities are the same, although larger institutions often opt to purchase more servers. And those servers could be quickly overloaded if users aren’t efficient with their use of the advanced communication tools.

A comparison of image quality using Pegasus Imaging’s JPEG 2000 compression (left) to standard JPEG compression (right). Both images are highly compressed from a raw image to approximately 15KB each.

Size Matters
“The sizes of the images are continuing to increase as digitizing advances,” says Will Clonts, medical imaging business development manager for Pegasus Imaging Corp (Tampa, Fla). “File sizes, numbers of slides, and images per study are [all] increasing. [Users] need to deliver more images over a network—quickly.”

Increasingly, companies are boosting transmission speed by utilizing image compression applications, or wavelet compression, like Pegasus’ JPEG 2000. Wavelet compression allows images to be condensed so that they can be transmitted faster to the end users. For example, an image compressed at a 10:1 ratio to be transmitted 10 times faster than the original image.

“It’s a revolution,” Clonts exclaims. “It allows radiologists to view images faster and see what they want to see faster and more efficiently. And it conforms to DICOM.” Some type of image-compression protocol is included with most teleradiology systems.

But the compression of images inevitably means some loss of integrity in the transmitted image. If systems are capable of compressing an image to a tenth of its original size, the usability of that image could suffer. The acceptable compression ratio varies with original image quality and modality. However, these quality compromises most likely will be unimportant when the images are not intended for complete diagnostics.

“Some compression algorithms can do about a 2.3:1 ratio with no loss of information,” says BRIT Systems’ Mulvihill. “With CT or MRI, you might be able to use 5:1 or 8:1. But you absolutely should not use teleradiology for mammography. People want to digitize that film at a high enough resolution, but we’re not there yet.”

Monitoring Progress
As digitally transmitted images get more sophisticated, so must the monitors used to view the images. Although teleradiology’s on-call functions tend to work well on a standard PC monitor, radiology departments demand more of the hardware they use on-site.

“They usually know what they’re looking for,” says David Payne, an account representative for Data-Ray Corp (Westminster, Colo), whose customers are primarily large university hospital facilities and imaging centers.

Data-Ray’s newest panel, the Ad Cal Phase II, was introduced at RSNA 2003.

And what they want is technology that keeps pace with the applications they’re using. Data-Ray offers the only 20-inch panel on the market for image viewing, Payne says. At RSNA last November, the company unveiled the Ad Cal Phase II, an 11-bit monitor with self-calibration that distinguishes more than 7,000 shades of gray.

Payne says, “It makes the images more precise,” which is increasingly important as people move away from printouts and interpret images on-screen. “And radiologists can read them more quickly. They want to be able to read faster, because that’s how they’re getting paid.”

Teleradiology in Action
Paul Elliott, north central region VP at DMS Health Group (Fargo, ND), is enthusiastic about the power of teleradiology. Elliott oversees his company’s fleet of mobile-imaging units that service nursing homes throughout the Twin Cities region of Minnesota.

“It’s helping us become more efficient,” he says. “We’ve switched from a film-based system. This fall, we implemented a network of computed radiography [CR] systems, strategically placed around the Twin Cities.”

Before implementing the teleradiology system, DMS’ radiology techs had to make frequent road trips over long distances to download the images taken at the nursing homes and transmit them to radiologists for reading.

Now they make shorter, less frequent drives to the six CR stations, which are tied to the main office through a T1 line with PACS. In addition to sending the newly created images, the PACS system automates the process of “prefetching” images of a similar body part of the same patient and sending those images to the radiologist—again, saving driving time and costs for an even quicker solution.

DMS has partnered with APEX Radiology Inc (Coral Springs, Fla), a teleradiology solutions provider, to make the images, dictation, and related files accessible on the Web.

“It doesn’t matter how fast you get to the nursing home if you can’t transmit those images quickly,” Elliott explains. “Our level of patient care is increasing greatly. Our radiology [technologists] can spend less time on the road. In a portable business, they’d rather be doing X-rays than driving.

“And we’ve gained four new customers without having to add staff,” he continues. “We have PACS in place, so we can add business without adding capital expenses. From a portable standpoint, we have a jump on the competition. Most are privately held and don’t have the capital.”

Capital expenditures didn’t cause DMS to hesitate for even a moment. According to Elliott, the company expects an extraordinarily short time frame for recouping the implementation costs of the system.

Left: “In teleradiology, it is imperative that images appear the same, no matter what display device they are viewed on. Calibrating all workstation displays to conform to the DICOM grayscale calibration standard optimizes the display of images in remote locations. As long as the digital driving levels of the image are preserved and passed to the remote workstation for display, the resulting viewable image should be the same, [regardless of the] workstation. Testing of the workstation calibration prior to fielding and periodically thereafter is a critical feature of a teleradiology process. Here, John Weiser, PhD, of Xtria Healthcare performs DICOM grayscale calibration analysis on several high-resolution flat-panel monitors before deploying them into a hospital.”

—John Romlein MSE, VP of Xtria Healthcare

Looking to the Future
Even as the industry is experiencing its wildest success, the future of teleradiology could be its gradual demise—in name, at least. Its own successful adaptation of DICOM standards and PACS connectivity means it’s being absorbed by the PACS with which it’s designed to interface.

“Teleradiology, as part of the changing model, is disappearing as a separate technology,” Algotec’s Margolin says. “It’s becoming a part of PACS. It almost becomes a side effect of the larger system.”

And the price of PACS continues to decrease from the intimidating seven-figure expenditures of yesterday. It has become more modular and affordable, costing several hundred thousand dollars instead of the recent million-dollar price tags.

Even if the term teleradiology doesn’t survive the decade, its functions will continue to shape the industry.

Holly Celeste Fisk is a contributing writer for Medical Imaging.