MR scanners, technology move to center stage

November 5, 2004

When the exhibit floor opens at the RSNA meeting, MR vendors will reveal products and technologies that reflect what they believe their customers need. Philips will unveil the first commercially viable 1T open system. Siemens will unite new and old scanners under a single coil technology. GE will reach the pinnacle of data processing. Toshiba will offer upgrade paths for customers at both mid- and high-field. Hitachi will fulfill promises made last year by showing commercial upgrades to its midfield Airis and higher field Altaire platforms.

Although each achievement has its merits, Philips' will stand out from the rest, if only for the length of time it has been awaited. The industry first promised a 1T open MR scanner five years ago; Philips will fulfill that promise this year with the Panorama 1.0T. The scanner, which cleared the FDA in July, was scheduled for an October installation at a site in Las Vegas. Full production is slated for next year.

The actively shielded vertical-field superconducting magnet operates on the same platform as the company's cylindrical Achieva but relies on a host of specially designed coils. With these coils, the Panorama 1.0T offers image quality and scan speed comparable to a 1.5T scanner, according to Jacques Coumans, Philips vice president of MR global marketing. Throughput is boosted by a wheeled patient table that docks with the scanner. A site purchasing two tables can use one to prepare a patient while another patient is in the scanner.

Purchasers of the new system may enjoy an additional benefit: Preliminary tests done by Philips indicate that the Panorama 1.0T produces fewer artifacts than 1.5T systems when running cardiac protocols.

"We have seen fantastic coronaries, fantastic functional studies of the heart," Coumans said. "We ourselves were very surprised by it."

Although Philips may become the first company to mass-produce a 1T open, it was not the first to promise one. Siemens Medical Solutions unveiled a mockup of a 1T open scanner a year before Philips did and eventually installed three Rhapsody scanners, but it subsequently abandoned the product. Siemens first cited difficulty in crafting a design that could be manufactured economically and then claimed that the market had lost interest in high-field open scanners.

Siemens' solution for imaging of claustrophobic or large patients is the ultracompact cylindrical 1.5T Espree scanner with an opening similar to those found on CT scanners. The scanner, released in July, measures just 125 cm wide and has a 70-cm-diameter bore. The company will promote it at the RSNA meeting as the first in a new class of MR scanners: an open-bore category unlike any previously seen. Its success will depend on the open-mindedness of booth visitors.

The company's flagship premium-performance Avanto 1.5T scanner, released at last year's RSNA meeting, has a 60-cm-wide bore, just 10 cm smaller than the Espree. Philips' Achieva also has a 60-cm bore diameter.

While the question of whether Espree constitutes a new category might be debated, there is no argument that it is roomier and more compact than any other MR scanner on the market. It is Siemens' answer to the need for a less imposing scanner than the high-field cylindrical type.

The company is not, however, giving up on open scanners of traditional design. Just weeks after unveiling the Espree, Siemens introduced the Magnetom C!, a clam-shaped system with a 0.35T permanent magnet. It is engineered to hit a sweet spot in the open market. Its field strength exemplifies midfield open products, which annually attract about 8% to 12% of the U.S. expenditures on new MR systems, according to Siemens. Until now, the company has been excluded from this niche, having only the low-field 0.2T Concerto.

The Siemens message this year will be a reprise of last year's theme, the total imaging matrix (TIM).

The whole-body coil technology, introduced at the last RSNA meeting, serves as an integrated set of surface coils that boosts the performance of Siemens scanners. Introduced on the Avanto last year, TIM has since been migrated to the Espree, Magnetom C!, and 3T Trio. All will be shown at this year's meeting, and booth staff will be talking up the availability of TIM as an upgrade for Siemens' Symphony MRs next year.

GE Healthcare will replay last year's theme as well, focusing on its Excite data pipeline. This year's debut of the Excite HD (high definition) will mark a milestone achievement for that platform, according to Dave Weber, Ph.D., manager of global high-field MR business for GE.

Excite HD was designed to support growth in increments of 16 channels, as in the current and future Excite HD 16, 32, and 48 versions. The key to unlocking this power is the capability of the HD platform to rapidly reconstruct data in up to 1700 frames of 256 squared matrices. This development is the culmination of a strategy to improve speed, resolution, and image quality in support of advanced applications, Weber said.

"This is the fulfillment of our original Excite strategy," he said.

Protecting customers' investments will take center stage at the Toshiba booth. Upgrades will be featured for every Opart 0.35T scanner ever installed, said Bob Giegerich, director of the MR business unit for Toshiba America. Four packages for owners and prospective buyers of the 1.5T Excelart Vantage will also be highlighted. These will range from 30 mT/m gradients with a slew rate of 50 T/m/sec to 30 mT/m gradients with a slew rate of 200 T/m/sec.

"Upgradability is something customers are looking for," Giegerich said. "They need to know their investments will be protected."