There will be few surprises in MRI at the 2001 RSNA meeting, mainly because vendors all but put their drawing boards on display last year. They plan to make good on old promises this year, commercializing the works in progress they showed at the last meeting-or at least providing more details about those products. Every level of performance will be featured, from 3-tesla to higher field opens, mid-field opens to conventional high-field systems, and general-purpose to optimized specialty units.MRI is booming and vendors want to keep the momentum going. At the start of the third quarter, MRI was on track for a record sales year in the U.S., with 461 units sold for revenues of more than $579 million, according to the National Electrical Manufacturers Association (NEMA), which tallies domestic sales of imaging equipment. The industry expects 3-tesla scanners to be a major source of revenue. This product area is among the most promising over the long term, and every MRI vendor will address it on the RSNA floor.
"We think it is the future of premium radiology and we are moving forward aggressively," said Dennis Cooke, general manager of global MR for GE.
In the past years, scanners above 1.5-tesla have been novelty items, serving mostly as demonstrations that massive systems, some of which towered several stories high, could be built. Production line units operated at 1.5 tesla or below, a ceiling defined almost two decades ago. With the preponderance of data submitted for machines at this level, the FDA anointed 1.5 tesla as a safe field strength, inadvertently erecting a barrier to the development of very high field strength systems.
That barrier has grown less restrictive as very high and ultra-high field systems have entered research and clinical operation. With increasing demand for machines with better signal to noise, GE Medical Systems began routine production of a 3-tesla unit optimized for neurological imaging more than a year ago. This unit, since modified for whole-body imaging, will be a major focus at the GE booth. By mid-September, GE had three whole-body units installed at clinical sites and expected nearly 20 to be operating by year's end.
Other vendors, notably Philips Medical Systems, will also feature 3-tesla machines. Philips plans to showcase clinical images from its 3-tesla whole-body system installed at the Institute of Biomedical Engineering in Zurich, Switzerland. The emphasis will be on cardiovascular imaging.
Philips will also be upping the ante in a looming battle over the use of sensitivity encoding technology, which the company calls SENSE. GE, Siemens, and Toshiba are developing their own versions of sensitivity encoding technology. At least two of these will appear at the RSNA meeting. GE will feature ASSET (array spatial sensitivity encoding technique); Toshiba will offer up Speeder. The names are different, but the approach is the same. SENSE, Asset, and Speeder acquire MRI data in parallel, affording the operator the choice of a faster scan, higher resolution images, or both.
Philips will report a dramatic improvement in SENSE that will enable its technology to increase speed or resolution well beyond the factor of two routinely possible with the initial version of SENSE.
"We will show clinically workable, artifact-free images with SENSE factors larger than eight," said Jacques Coumans, Ph.D., global marketing director for Philips MR. "This is a tremendous step forward."
Open scanners, particularly higher field products, will continue to attract attention. By the time of the RSNA meeting, Siemens' 1-tesla open system Rhapsody is expected to be installed at a German clinical site specializing in spine interventions. The first U.S. installation is scheduled to occur before the end of this year. The production line system will come equipped with advanced sequences, including turbo spin-echo and angiography.
"The system will not be as mature as our (conventional) 1-tesla, but it will have quite a bit of software on it," said Nancy Gillen, vice president of the Siemens MR division.
The status of open higher field scanners being developed by Philips and Marconi is less certain. Philips' bid to acquire Marconi was still pending at the time of this writing. Regardless of whether the acquisition occurs, Philips plans to show the first images taken with its Panorama 1.0T and to describe how this high-field open system will fit into its R&D strategy.
"We will indicate in our 'road map' much more clarity than we have before," Coumans said. "We will talk about future concepts in magnets: asymmetric and ultra-short magnets."
Sales of GE's 0.7-tesla Signa OpenSpeed and Hitachi's 0.7-tesla Altaire, the two commercially available higher field open systems, may benefit from the growing emphasis on high-performance open products. Interest in these systems could spill into the entire segment, which had been struggling until recently.
"We're going to see open MR coming back in terms of market share, and fueling that will be the high-field performance capabilities of open MR," said Sheldon Schaffer, vice president and general manager for MR at Hitachi Medical.
Most vendors will also use the RSNA exhibit to introduce enhancements at a variety of field strengths. Among them will be an enhanced cryogen handling system for Toshiba's 0.35-tesla Opart, and system upgrades designed for Siemens' conventional scanners, the 1-tesla Symphony and 1.5-tesla Harmony. Siemens' 0.2-tesla open-style Concerto, unveiled at last year's RSNA meeting, will also sport enhancements this year.
New products provide excitement on the exhibit floor, but existing products and upgrades are the companies' bread and butter. GE sales figures for upgrades account for the majority of the industry's upgrade revenues reported to NEMA, Cooke said. This success is a result of the company's efforts to design new devices such as the dual-gradient TwinSpeed, which is compatible with the installed base of high-field Signa products. The two gradients built into TwinSpeed allow general-purpose and specialized cardiac imaging. GE engineers have also broadened offerings within market segments, adding the 0.35-tesla Ovation to the company's open scanner offerings, for example.
"We have never had so many products in so many segments coming forward," Cooke said. "A lot of what we are going to emphasize is real and is shipping in quantity."
