MRI product launches usher in era of short-bore magnet design

Picker goes public with new magnets before GE and Siemens

The summer doldrums have been broken with a series of product introductions that promise to redefine the look and performance of high-field, whole-body MRI systems.

Picker International got the jump on rivals GE and Siemens last week when it formally raised the curtain on the new 1.5-tesla Eclipse and 1-tesla Polaris scanners, the successors to Asset and Edge in Picker's high-field superconducting product line. Eclipse and Polaris are 22% shorter and 30% lighter and feature substantially wider patient bores than their predecessors. As a result, they are less intimidating to patients and easier to site for owners.

Customers can expect to hear similar sales pitches when GE and Siemens unleash marketing efforts for their own new short-bore offerings in September. GE will tout the advantage of Horizon LX, equipped with a compact GE CX magnet that was approved by the Food and Drug Administration last November. Horizon LX is packaged in either 1-tesla or 1.5-tesla configurations. Preparations are under way in Erlangen, Germany, for Siemens' worldwide launch of its short-bore 1-tesla Harmony and 1.5-tesla Symphony magnets. Their marketing promotions will kick off in late September, according to Allen Miller, senior manager for public relations at Siemens in Iselin, NJ.

These three initiatives have led consultant Robert Bell, who has field-tested the new GE and Picker systems, to label 1997 as the year of the compact magnet. The engineers who designed the new systems attempted to preserve the historic advantages of high-field MRI-such as high signal-to-noise, small fields-of-view, and fast slew rates-as they incorporated design characteristics that helped low-field, open MRI gain popularity, he said.

"This is the starting point for a new generation of high-field systems that are shorter and lighter and have smaller fringe fields than systems currently in service," Bell said. "They incorporate, as much as possible, the ability to open up the environment of the magnet, thereby reducing claustrophobia."

While Picker, Siemens, and GE are breaking new ground for their customers, the short-bore design concept is not exactly new. Philips Medical Systems introduced its Gyroscan NT series, the industry's first short-bore, whole-body scanners, at the RSNA show in 1993 (SCAN 12/29/93). Available in 1.5-tesla, 1-tesla, and 0.5-tesla models, the NT scanners solidified Philips' position in the high-field market sector. About 1300 of the compact scanners are installed around the world, according to Christopher Farr, MR/CT marketing director for the Shelton, CT, vendor.

Beyond the performance characteristics of the products themselves, the Picker, GE, and Siemens launches are noteworthy for the unheralded way the systems crept into the marketplace: All six systems have been cleared by the Food and Drug Administration. Picker secured clearances for Eclipse and Polaris in February, while Siemens' Harmony and Symphony were okayed in June and August, respectively. In all three cases, sales and shipments commenced before the companies publicly announced the new products.

Picker, for example, concentrated on its installed base and customers who were on backlog before going public, according to Larry Wells, Eclipse product manager.

"We were sensitive to our installed base. We wanted to make sure these customers were happy and understood the upgrade path, and that they didn't feel left behind," he said.

Picker started manufacturing Eclipse and Polaris in June. The first production unit is operating at an undisclosed Pennsylvania site. Two more 1.5-tesla systems have been shipped to U.S. customers, and a third system is in transit to Korea, Wells said. The company has built up a large backlog from the conversion of Asset/Edge orders to the new configurations, and the factory is running two shifts, he said.

GE's sales force also started selling the new Horizon LX in June, according to Yoshiaki Fujimori, general manager of global MR operations for the Milwaukee vendor. The company aimed at having a base of systems and customer endorsements in place before launching a pre-RSNA promotion, he said.

The magnet of Picker's Eclipse is slightly over 6 feet long, more than 2 feet shorter than Edge. With cryogens, Eclipse weighs 9700 pounds. Cryogen refills are needed every two years. PowerDrive gradient coil options rated at 16-, 20-, or 27-mtesla/m peak amplitude are available. Either Picker system can be installed in 325 square feet of floor space. The patient apertures of the two models were expanded 5%, from 58 to 61 cm, and the patient bed was widened to be more stable and comfortable for patients up to 440 pounds, Wells said.

GE made similar improvements. The 1-tesla and 1.5-tesla versions of Horizon LX are 6.8 feet long. With cryogens, the 1.5-tesla model weighs 8650 pounds, and the 1-tesla model weighs about 7900 pounds. Both scanners need annual cryogen refills and can operate in as little as 243 square feet of space. Both also feature 60-cm-diameter circular patient bores and removable patient tables that handle patients up to 330 pounds.

Siemens officials are withholding details about Harmony and Symphony until the products are formally introduced. According to outside sources, however, the 1-tesla Harmony will replace Magnetom Impact. Harmony performs all the clinical applications available as standard or optional features on Impact, but is housed in a much smaller, lighter package. A Siemens official confirmed, however, that the 1.5-tesla Vision will remain a part of the product line as a high-performance research-oriented system.

Regardless of how these details shake out, it is clear that the slow days of buying and selling high-field MRI systems are over. Customers and manufacturers can look forward to the most interesting sales season in years.