Agfa, Fuji and Kodak weigh in at RSNA showThe technology arms race is escalating in computed radiography,to the benefit of equipment purchasers. Competition between vendorsis driving improvements in CR's spatial resolution that bringit closer to
The technology arms race is escalating in computed radiography,to the benefit of equipment purchasers. Competition between vendorsis driving improvements in CR's spatial resolution that bringit closer to film, while CR's cost-benefit ratio is improvingas well. The market may be headed for a patent showdown betweenFuji and Agfa, however, over technology used in their CR readers.
Fuji has held a dominant position in CR since introducing thetechnology in 1981, with Fuji-manufactured CR machines makingup about 97% of the U.S. market, according to the company. Fujisells CR readers on an OEM basis through several major multimodalityvendors, including Philips, Siemens and Toshiba.
The growing emphasis on PACS and digital imaging has sparkedrenewed interest in CR as hospitals look for ways to bring conventionalx-ray into their networks. To many vendors, Fuji's market shareis a tempting target, and Agfa, Kodak and Du Pont showcased technologyat the 1994 Radiological Society of North America meeting thatcould chip away at Fuji's position. Fuji responded with new productsof its own.
New technologies displayed at the RSNA conference included:
In addition to these products, Philips' ThoraVision, a selenium-baseddigital chest system, was displayed for the first time with Foodand Drug Administration clearance (SCAN 10/12/94).
Fuji's FCR 9501 is a dedicated chest version of its fifth-generationFCR 9000 product (SCAN 11/9/94). It features throughput of 12014 x 17 plates an hour with a list price of about $325,000, accordingto John Strauss, national marketing manager for CR at Stamford,CT-based Fuji.
The vendor's HQ upgrade is an option that brings 4k x 4k resolutionto new Fuji CR products as well as its installed base of fifth-generationreaders: FCR 9000, FCR 9501 and AC-3. HQ should satisfy thoseradiologists who are concerned about CR's spatial resolution,according to Strauss.
HQ uses Fuji's fifth-generation phosphor imaging plates, whichhave a smaller phosphor particle size and a higher phosphor particlepacking density. Fifth-generation readers also have new higherpowered solid-state lasers and improved optical scanning systems.This helps the systems read plates more rapidly to make a 4k x4k acquisition quickly. It also allows printing to 14 x 17 films,an improvement on the 2k x 2.5k and 10 x 14 films that previouslywere standard. Hard copies in the 14 x 17 size could be made with2k images, but they required image interpolation that resultedin a loss of sharpness, Strauss said. In addition to the boostin the acquisition matrix, HQ's resolution is five line pairsper mm for all plate sizes, also a technical improvement.
Kodak's Model 400 is a general-purpose CR reader, unlike Kodak'searlier offering, Imagelink Critical Care System, which is targetedat ICU/CCU applications.
Model 400 uses a new GPU 25 phosphor-plate material, whichenables quicker imaging with less radiation exposure than thevendor's previous plate material, according to Michael Moehring,product line manager for Kodak in Dallas. It offers the radiographicequivalent of 250/300 speed screen-film systems, Moehring said.Spatial resolution is 2k x 2.5k at 2.5 line pairs per mm. Throughputis 50 plates an hour. Kodak has FDA clearance for Model 400 andis marketing it at a list price of $175,000.
Model 400 users can achieve better image quality with new storagephosphor screens and cassettes that boost resolution to five linepairs per mm. The screens and cassettes are targeted at extremityimaging, according to Moehring.
In its RSNA booth, Agfa displayed ADC 70, a new CR reader thatit is bringing into U.S. and European markets this year. ADC 70supports multiple cassette sizes from 14 x 17 to 8 x 10 and hasa throughput of 70 plates an hour in the 14 x 17 format. It isa 2k x 2.5k x 12-bit reader.
A unique feature of ADC 70 is its stacking mechanism, whichallows technologists to stack multiple cassettes into the readerrather than feeding them one at a time, according to Vishal Wanchoo,director of electronic imaging systems. The system also has anID flasher for downloading patient information from a radiologyinformation system to the cassette.
Patent showdown looms. Agfa may run into legal interferencefrom Fuji when it introduces ADC 70 in the U.S. due to Fuji claimsthat Agfa's technology infringes on its CR patents. Some of thosepatents are due to expire this year, but core patents on bariumfluorobromide storage phosphor material are valid until 1998 andother patents are valid for years after that, according to Fuji'sStrauss. Agfa has been prevented from introducing CR readers insome markets due to the patent issue (SCAN 1/30/91).
Agfa has changed ADC 70's laser optics and storage phosphor-platetechnology to avoid infringing on Fuji's patents, according tothe company. Fuji, however, believes that ADC 70 still conflictswith its patents on barium fluorobromide storage material, accordingto Strauss. Barium fluorobromide is the only storage phosphormaterial that's viable for medical applications and Fuji has broadpatents on the technology, Strauss said. Fuji may resort to legalaction if Agfa begins selling ADC 70 in the U.S.
"We would consider legal recourse," Strauss toldSCAN. "Japan (Fuji's Japanese parent) sees enough similaritiesin the design of ADC that (Agfa) will be in conflict for 10 years."
With regard to Kodak's Model 400, Strauss said Fuji has nottaken a close look at the technology behind the product, but ifit does not differ from Kodak's Imagelink Critical Care Systemit will not have a patent interference problem. The earlier Kodakreader has mechanics that differ from Fuji readers. Kodak alsolicensed imaging plate technology from Fuji.
Taking an entirely different tack from phosphor-based computedradiography systems is Du Pont. The film and PACS vendor displayedwork at the RSNA show on what it calls direct radiography, whichuses digital detector technology based on the use of photoconductors.
Unlike phosphor-based CR or screen-film systems, photoconductorsconvert x-ray photons into electrical signals without the useof light. Photoconductors may be able to offer higher resolutionthan CR systems because they avoid light scatter common to storagephosphors, according to Ed Lawrence, technical associate for digitalradiography for Du Pont, of Wilmington, DE.
Photoconductors were used in the past on Xerox's xeromammographysystems, which employed a selenium-based photoconductor material.Philips' ThoraVision system is a more recent example of a selenium-basedphotoconductor. Du Pont plans to release more details of its technologyat the International Society for Optical Engineering's (SPIE)medical imaging conference in San Diego at the end of this month.The company hopes to have a product available in the next threeto five years.