Home

Cover Story

Table of Contents

E-Newsletter

Article Archive

Editorial Calendar

Datebook

Writers' Guidelines

Orgs/Links

Opinion Polls

Reprints

Forum

For other articles and previous issues click here.

June 7, 2004

Monitor Migration
By Dan Harvey
Vol. 5 No. 12 p. 18

One of the chief benefits of a PACS environment is the ability to easily distribute and view images at numerous locations throughout an enterprise. Outside the radiology department, healthcare professionals use workstations in operating rooms, emergency departments, and intensive care units.

Because a PACS environment requires such an enterprisewide workstation distribution, the cathode ray tube (CRT) monitor became a ubiquitous presence. However, liquid crystal display (LCD) flat-panel monitors are slowly but surely replacing the once ever-present CRT monitors. LCDs offer several advantages over CRTs, not the least of which is markedly improved image quality.

High-quality display is important to PACS, but not every system user needs the same diagnostic quality and high-resolution display monitors required in a radiology reading room. Organizations making the transition to PACS have reduced their implementation costs by using the appropriate mix of viewing stations throughout the enterprise. “Hospitals, like companies, operate on a budget and most likely would not be outfitted with the most expensive, high-quality displays at every workstation,” says George Rigas, medical product manager with Matrox Graphics Inc., a Montreal-based manufacturer of medical flat-panel monitors.

High-quality displays and display controllers are required for diagnostic stations, Rigas points out. However, lower-performance workstations and displays are acceptable for review stations where users such as referring physicians examine the radiologist’s diagnosis.

Planar Systems, Inc., a flat-panel display manufacturer based in Beaverton, Ore., takes a three-tiered approach, offering different levels of monitors to match users’ need. “Obviously, different practitioners with different backgrounds and different viewing needs may not need native gray scale and the ultrahigh resolution, so we approach the market with three very distinct segments,” reports Dave Hebert, Planar’s product manager.

The first segment focuses on diagnostic review, which is typically done by a radiologist in a reading room. Radiologists need the highest resolution, the native gray scale, and automatic resolution and calibration—all features essential for critical diagnosis.

Different Jobs, Different Displays
The second segment is for referral review, in which image quality standards wouldn’t be quite as high. “Typically, this segment would include practicing physicians and specialists who are looking over images already evaluated by a radiologist,” says Hebert. Users in this segment confer with radiologists about the images; therefore, the monitors could be less expensive 2-megapixel resolution with manual calibration. “These displays are cost-effective, so you can distribute [more of] them throughout a system, saving some money,” says Hebert.

The third segment is displays for clinical review. General practitioners, nurses, and support staff review the images but not to make a diagnosis. They use the monitor to see the image in the context of the rest of the work they’re doing with the patient.
“That is the breadth and the difference that we feel is appropriate throughout the entire hospital,” says Hebert.

The increasing presence of LCD was apparent at recent major meetings, where LCD monitors took up more and more space on the exhibition showroom floor. Such high-profile showcases led to predictions that LCDs would dominate the monitor market and make CRTs obsolete. “If the exhibitions at conferences such as RSNA 2003 and European Congress of Radiology [ECR] 2004 are a reflection of what is and will be happening in hospitals, there certainly seems to be fewer and fewer CRTs,” says Rigas.

LCD technology has become the dominant presence in some monitor markets. “It’s already happened in the commercial sector,” says Kaz Kajikawa, product manager for Eizo Nanao Technologies, the Cypress, Calif.-based subsidiary of Japan’s Eizo Nanao Corporation, a manufacturer of display products. “Now, the LCD is taking over the medical market, too.”

“[In the home consumer market] all sorts of display technologies are migrating to LCD, as consumers are targets for flat-panel televisions, PCs, laptops, PDAs, in-car DVD players, portable electronics, and big-screen home entertainment,” says Rigas. “Why shouldn’t hospitals or medical institutions benefit from this large-scale transformation to LCD technology?”

Transition Time
Rigas says LCD offers a higher overall quality in terms of maintenance, support, and the ability to communicate within a networked environment typified by PACS. Appropriately, LCD technology now represents most of the new display purchases, and fewer CRT monitors are being developed and introduced into the market, he says. CRTs haven’t vanished just yet; medical institutions are not in a big hurry to throw their functioning older monitors. Instead, says Rigas, they are waiting for their CRTs to be amortized or until they need to be replaced. As this happens, he says, the days of bulky CRTs will become numbered. Still, the final good-bye is a little farther down the road. “Some institutions can migrate to LCDs entirely, some partially, and some not at all,” he reveals. “It’s all based on their individual budgets and funding levels, timelines, and comfort levels to change.”

One main reason why the LCD market is getting stronger and growing rapidly is that prices are starting to come down. Until recently, the use of flat panels in PACS environments was limited because of price. Initial purchase costs—typically twice that of CRT monitors—proved prohibitive for many facilities. But the usual marketplace dynamics for technology have come into play: As demand increases, manufacturers have increased LCD production, which is followed by the inevitable price reduction.

As the cost difference lessens, the advantages of LCD technology over CRT become more accessible. These advantages, Rigas says, include lower power consumption and emissions, lower heat and better cooling, manageability across a network, and fewer mechanical and electrical parts to replace.

Image Quality
“Flat panels have distinct advantages that CRTs will never be able to address,” agrees Hebert, “such as uniformity and stability. Over time, the image quality in an LCD doesn’t change. The backlights will drop a little in luminance, but nowhere near a CRT’s drop.”

With CRT, an electron beam hits a phosphor screen, and the electron energy transforms into visible light photons. Eventually through normal usage, the electron-emitting cathode ray tube—the most integral part of the monitor—needs replacing. Because of the high cost of a new tube, you may as well just buy a new monitor.

With an LCD monitor, a bright backlight is projected onto a screen comprised of liquid crystals. As with the CRT’s light photons, the LCD backlight will diminish over time, but it is easier and less costly to replace than a cathode ray tube. A replacement costs roughly $500.

The inherent advantages of LCDs make them considerably less expensive to own and operate. Flat panels are easier to install, are more reliable, require less maintenance, and last much longer. These benefits combine to bring down the total cost of ownership—a major selling point for LCD technology. “Operating costs and longevity are the payoffs with LCD,” says Kajikawa. “CRTs, for medical purposes, are very expensive to operate.”

“Early LCD adopters were hit with the highest costs, as new technology needs to be paid off,” says Rigas, “but, eventually, as the community at large embraces the features and sees a greater return on investment, more and more buy LCDs, and costs start to fall as manufacturers perfect the process.”

In addition to their operational benefits, the monitors are environmentally safe and they take up less space, which makes LCD monitors the more versatile piece of equipment. This advantage is especially important in areas where space comes at a premium, such as emergency departments, intensive care units, and operating rooms. Larger and heavier CRTs present logistical problems.

LCDs also require less servicing than CRTs, as most manufacturers include automatic adjustments and calibrations in their products. But the real benefit is image quality. “The images are spectacular,” says Hebert.

Product Overview
Many companies in the medical monitor market started out developing display technology for other business sectors before bringing their expertise into the medical industry. For more than 28 years, Matrox has been developing monitors for a variety of fields. At one point, relates Rigas, customers and display makers approached the company to develop products for the radiology market. In response, the company developed display controllers that address specific medical challenges and tailor unique solutions. “Matrox is not producing a mass market or commodity medical solutions because medical requirements are very specific,” he reports. “Having been in the graphics business for over a quarter century, we have the experience and knowledge to design display controllers specifically for the medical market with features related specifically to medical professionals.”

Matrox offers a complete line of medical imaging solutions for review, diagnostic, and educational stations. Its Matrox MED Series, designed for diagnostic PACS stations and a range of modalities, provides 10-bit gray scale that supports accurate diagnosis. The line includes the Matrox MED2mp, MED3mp, and MED5mp.

The Matrox RAD Series—including the RAD2mp, RAD9mp, and RADQ2mp—is designed for both review and diagnostic stations. It supports both color and grayscale configurations in both stretched or independent modes. The series also features Matrox’s ExtendiGray technology. “This accurately converts color displays into gray scale, reducing color distraction during readings, and allows for concurrent execution of color and grayscale applications on a single grayscale desktop,” says Rigas.

Like Matrox, Eizo developed products for other industries before applying its expertise to healthcare. Kajikawa reports that the company has been producing high-end monitors for various specialists for more than 30 years and started producing its LCD monitors seven years ago, primarily for PACS in its medical market. Its medical line includes grayscale and color LCD monitors for use in radiology, endoscopy, angiography, sonography, CT, and magnetic resonance tomography. All products feature the company’s own microchip and sensor. The monitors offer resolutions ranging from 1.3 to 3 megapixels.

In March at ECR 2004, Eizo showed off its RadiForce series of medical display systems, its new 2-megapixel monochrome and 1-megapixel color monitors, and spotlighted its new calibration and quality control software for the series.

Eizo’s RadiForce monitors include 1,531 different grayscale values, 256 of which can be displayed simultaneously. The monitors have an automatic control and calibration. The 2-megapixel model includes a hardware pivot function that produces high-quality reproductions and a microchip that calculates picture signals in landscape or portrait format, which reduces the burden on the computer system. The 3-megapixel RadiForce monitors are controlled by a specially developed two-port graphics card.

Eizo’s RadiForce color monitors are intended for the digital display of multicolored pictures or black-and-white pictures marked in color. These monitors are typically used in nuclear medicine, color duplex sonography, and endoscopy. One notable feature about the color monitors is that the high-contrast panel is unaffected by the angle of view. Users see a uniform color reproduction regardless of the angle at which they view the screen.

Hardware and Software
A 20-year-old company, Planar Systems, Inc. has been in the radiology LCD market for more than five years. It now offers a complete suite of cost-effective medical display products, including its Dome line of displays, graphics boards, and quality management software for medical imaging.

The Dome display line—which includes the Dome C2, C3, and C5i and the Dome QX—provides diagnostic-quality images throughout an entire enterprise. They come in 2-, 3- and 5-megapixel resolution, grayscale and full-color, and diagnostic- and referral-grade. Dome displays are available with Dome CXtra software, which provides consistent calibration.

Each product in the display line features extremely high luminance and provides grayscale fidelity and image quality in a DICOM-calibrated monitor. The Dome C2, designed for referral and low-resolution imaging such as MRI, is a flexible 1,200- X 1,600-pixel grayscale flat panel that can display images in portrait or landscape mode. The Dome C3 flexible 1,536- X 2,048-pixel grayscale flat panel, designed for midresolution grayscale imaging, also displays images in portrait or landscape mode. The Dome C5i flat panel was designed specifically for the high-resolution grayscale imaging necessary to radiology.

The medical market for LCD technology will continue to grow as prices steadily drop and prospective users become aware of its many inherent benefits. The big-picture result will make PACS implementation seem more feasible and affordable to more hospitals. Companies instill their product lines with a versatility and mix of capabilities that will enable the most appropriate distribution of display technology throughout an enterprise that has deployed PACS. How display monitors are distributed, says Rigas, is up to an individual facility, with the decision based on its own procedures and standards for diagnostic and reviewing stations and what types of workstations are used for each.

— Dan Harvey is a contributing editor for Radiology Today.

Subscribe to Radiology Today Magazine!