Hitachi releases 0.7-tesla open MRI scanner using superconducting technology

Hitachi will soon release a 0.7-tesla open MRI scanner based on superconducting technology. The Japanese company introduced its sales staff to the new product, called Altaire, on Nov. 2, following receipt of FDA clearance less than two weeks earlier.

Hitachi planned to blitz the trade media with mailings about the new product, beginning on Nov. 6 and leading up to a grand unveiling at the RSNA meeting at the end of the month. The timing couldn't be better, said Sheldon Schaffer, vice president of marketing for Hitachi Medical Systems America. The company plans to use the international meeting as a launchpad for the new system.

"The marketplace has been mostly divided to the point that customers have to purchase either an open system or a high-field system," Schaffer said. "We've been working hard to bridge that gap. Altaire represents that effort."

Altaire marks a leap in both technology and price for Hitachi. The company lists its Airis low-field open MRI scanner for less than $1 million. Buyers of Altaire will have to dig deeper and come up with about $1.5 million.

"But along with that high-field price you will see throughput in line with high-field systems," he said.

Like GE, whose Signa OpenSpeed generates a 0.7-tesla magnetic field, Hitachi plans to market Altaire as a high-field system, even though high field traditionally begins at 1 tesla. Billing Altaire as a high-field system is justified, Schaffer said, because the system's vertical field generates images comparable to those obtained with a conventional high-field scanner.

Images supporting that claim have so far come only from a Hitachi engineering bay; clinical sites have not been installed. Now that FDA clearance is in hand, however, the company expects to move forward quickly with sales and installations.

Hitachi popularized the open concept in the mid- to late 1990s with sales of its Airis products. The vendor's efforts to penetrate the high-field market with conventional closed systems have not fared well. Hitachi hopes to build Altaire's fortunes on the company's reputation, engineering strengths, and installed open-field base.

"We're looking to extend our customer base beyond mid-field open MRI and we believe Altaire will give us the opportunity to do so," Schaffer said.

Altaire's design is an outgrowth of work done on open low-field scanners. Engineers in Japan modeled the new system on the architecture of the Airis II, expanding the size and field strength by introducing superconducting magnet technology. Like the lower field systems, Altaire has an asymmetric gantry with two posts separating the vertical magnets. The patient gap is 47 cm. Gradients operate at 22 mtesla per meter with a slew rate of 55 tesla per meter per second.

"The intent was to provide high-field performance using vertical field magnet technology, along with the experience and expertise that Hitachi has gained over the past few years in vertical field magnet design," Schaffer said.

Integrating superconducting magnet technology into an open configuration presented a formidable challenge, particularly because Hitachi's previous experience with vertical

magnets on Airis systems was based on permanent magnet technology. A key consideration was development of a refrigeration unit that reduces the need for cryogen refills to once every year or two.

In its current configuration, Altaire supports common high-field imaging protocols, including echo-planar imaging, perfusion- and diffusion-weighted imaging, and true fat saturation. Echo times of around 2 msec can be achieved for fast spin-echo imaging.

"For customers who want an open MR system but have not purchased one because they need the performance of 1.5 tesla, this product will allow them to reconsider their decisions," Schaffer said.