BY ROGER LINDAHL

Attendees will see the ongoing efforts of vendors to improve flat-panel detectors and image processing

A quick stroll through the exhibit hall at this year’s RSNA meeting and one message about digital x-ray will come through crystal clear: Computed radiography is thriving. The CR market retains its momentum as users show appreciation for stimulable phosphor technology’s low cost and its ease in upgrading standard x-ray systems.

Technological upgrades to CR this year include efforts to improve the image quality of the digital technology. There will also be less expensive versions of CR that package image processing and PACS capabilities into low-end tabletop phosphor plate readers.

Sales of digital radiography (DR) systems utilizing flat-panel digital x-ray detectors have been slow to take off following the introduction of several new commercial systems at last year’s RSNA meeting. New DR systems to be highlighted at the conference this year focus mainly on expanding applications beyond dedicated chest imaging.

DR vendors will also show ongoing efforts to improve flat-panel detectors and image processing. One reason shipments have been sluggish this year is that the flat panels have proved complicated to develop and produce in larger quantities.

“The development of flat detectors is taking longer than the industry expected,” said George Mitchell, Siemens product manager for R&F and multipurpose systems. “There is significantly more demand (for DR systems) than we can ship.”

DR also remains substantially more expensive than both CR and standard x-ray, said Kevin Hobert, global manager of digital x-ray for GE Medical Systems. The cost differential of DR involves both the flat panel and workstation technology, including image processing and acquisition software. Costs, particularly on the workstation side, are likely to come down as volume rises.

Advantages of DR are found in the elimination of film and film processing, greater speed and patient throughput, and improved image quality at lower radiation dosages, he said.

DR offers “better contrast detectability but also a wider dynamic range and the ability to do a lot of image processing, which you could never have done with film,” Hobert said.

For some, though, the technological performance of flat panels, while improving, still has a way to go to justify the cost of their use in radiography.

“The resolution is not quite there yet,” said Tom Kloetzly, Picker International global sales manager for x-ray. Picker uses a flat-panel detector for CT interventional guidance but is holding off on general radiographic applications.

Customer queries to Picker regarding DR picked up after last year’s RSNA meeting but fell off again as expense and product deliverability became issues, Kloetzly said. On the other hand, flat-panel performance has improved considerably over the past year, said Tom Giordano, business unit director for radiography and PCR at Philips.

“The quality of panels coming out—their sensitivity and responsiveness—is far more consistent this year than last year,” he said.

Technological developments in CR are improving image quality, as witnessed by Fuji’s new dual-side phosphor plate reading technology. Advocates of DR hint at improved detection efficiency using flat panels rather than CR’s “indirect” method, said Clay Larsen, vice president of marketing and network development for Fuji.

“We are demonstrating that storage phosphor has longer legs than anyone predicted and will go head-to-head with flat-panel chest units.”

What is often used as an argument against CR—the need to transfer phosphor cassettes from an x-ray system to a CR reader—can also be viewed as a practical advantage. Because CR plates fit in most x-ray systems that use film, conversion from analog to digital x-ray is easier and less expensive. Cost is also less when several x-ray units share a centralized CR reader.

Basic x-ray has been the last adopter of digital acquisition, and the transition to digital x-ray probably will occur little by little and in parallel with continued use of film, he said.

Many of the new digital x-ray products seen at the meeting this year involve improved workstations and display software. As vendors seek to increase incentives to shift to digital x-ray, they are focusing on simplifying the use of digital systems and enhancing their connections to image and information networks.

Persuading doctors and hospitals to go filmless involves development of the total digital x-ray concept and its link to other healthcare networks, said Don Volz, director of the x-ray business unit for Toshiba America Medical Systems.

“The real problems we see going all-digital (involve) acceptance of technology and getting the networks and distribution of information squared away,” he said.

WHAT TO LOOK FOR

Agfa. Aiming to build demand for its entry-level ADC Solo CR unit, introduced last year, Agfa will add a Windows NT-based PC workstation and software to improve image processing and PACS functionality. The strategy is called PACS-enabled CR. Agfa will also discuss scan-head technology under development that should reduce the size of CR and boost plate reading speed.

Canon. Last year, Canon introduced its CXDI 11 upright DR system. This year, the vendor has expanded its DR line and broadened clinical applications with the introduction of the CXDI 22. Using a universal stand, the bucky system operates both as an upright and table system.

Canon will also show Dynamic Range Compression software, which processes the DR image so that both soft tissue and bone structure can be viewed on one image. Its use should help speed throughput.

Fuji. CR’s image gets a boost as Fuji adds a dual-side reading capability to its cassetteless FCR 5501 digital chest unit, introduced last year. An imaging plate with a clear base is used in order to read the phosphor glow from both sides simultaneously. This makes more efficient use of the x-ray energy and produces better image detail, according to the company.

Fuji will bring a new QA workstation to the show, the 7071. Technologist review of digital images is enhanced through such features as the presentation of thumbnail images showing gray scale and patient ID. DICOM output offers PACS connection.

GE. Broadening its DR product line, GE will exhibit the Revolution TX/i table unit to accompany its Revolution XQ/i upright system introduced in ’98. After spending the first part of this year refining its flat-panel technology, GE has geared up production and shipments of XQ/i to about one a week and anticipates volume will continue to increase, resulting in the installation of 30 to 50 units in the first year.

Hologic. Following the purchase of Direct Radiography Corp. (DRC) from Sterling this year, Hologic will display the DR 1000 and DR 1000C systems, produced in a joint venture with Fischer Imaging and introduced last year. Fischer will also be showing the systems in its booth again.

Hologic will discuss some DRC flat-panel works-in-progress, including development of a high-resolution plate for use in mammography. The vendor established a new glass plate supplier relationship with Lucky Goldstar of Korea this year, which should aid flat-panel production.

Kodak. New CR digital x-ray capture products will be displayed in the Kodak booth, although the vendor is not discussing details. Kodak will also show Enhanced Visualization Processing image processing software, sold as an option to its CR products.

Konica. Expanding from its high-end CR position set with the introduction of the cassetteless Regius 333 dedicated chest system last year, Konica will display its cassette-based Regius 150 CR system. The vendor combines image processing with the CR reader in one unit that it expects to sell for about the price of a CR reader alone. This system will enable Konica to build new business in the conversion of existing standard x-ray systems to CR.

Lumisys. A viewing workstation and image archive have been combined with a CR reader in Lumisys’ new low-end CR offering, the iLuminator, which will sell for under $75,000. Lumisys hopes the new desktop CR unit will build on enthusiasm for its ACR 2000 desktop system introduced last year. At the right price, the company will try to persuade more users to dump their film processors and take x-ray digital.

Philips. As demand builds gradually for Philips’ Digital Diagnost bucky DR system, introduced last year, the vendor turns its attention back to ThoraVision, the first direct digital detector system to hit the market, in 1993. Originally designed as a dedicated chest unit, ThoraVision has been given greater utility through Philips’ Extended Applications Package software, which will be showcased this year. Philips is also assuring new ThoraVision customers that they can upgrade to more recent flat-panel detector technology for a set price in the future.

Picker. Although Picker uses a flat-panel digital detector in its FACTS (fluoro-assisted CT) interventional CT suite, introduced last year, the vendor believes that larger panel detectors for DR remain cost- prohibitive. Picker will show a new image intensifier digital R&F room, the Clinix-RF Plus, this year, which integrates control of the x-ray generator and digital processing in one panel. The system saves space and is easy to operate. Its digital processing has been designed to accept a flat-panel upgrade when that can be cost- justified.

Siemens. DR versatility was the objective of Siemens in the development of its Vertix FD system, which joins the Thorax FD upright and Multix FD table DR systems introduced last year. Vertix FD has an overhead tube stand and a wall stand that moves out, enabling both upright chest imaging and tilting bucky work. If desired, the overhead x-ray tube can be combined with both a bucky table and wall stand detector in a single room, decreasing overall costs.

Siemens will also show a new remote digital R/F system, the Iconos R200, which offers 1K or optional 2K matrix resolution.

Toshiba. Trade mark issues caused Toshiba to change the name of last year’s Symphony 1000 radiographic and R/F digital equipment package using Agfa CR technology to the Alliance 1000. This year, the vendor will expand its Alliance line with a lower cost configuration (not yet named) to allow easier access to digital x-ray.

Toshiba continues to work on flat-panel digital x-ray detector technology and will show works-in-progress results with a new DR technology that combines dynamic as well as static imaging. This DR technology converts x-rays directly to an electrical charge, which is then digitized. Most DR panels convert first to light and then to a charge.

Toshiba will also show a new CCD-based digital R/F system, the Efficiency 450D.

Trex. While Trex’s 4000M DR chest system, introduced last year, has been installed at over 20 European sites, it has been placed only at the National Institutes of Health in the U.S. Trex has not expanded its DR line this year but will introduce a new digital R/F system, the 2200I. This modular system is designed to offer rapid image capture with a 0.5-second fluoroscopy-to-photo-spot transition time.