GE introduces new MR/i series of short-bore high-field magnets

Company developed less intimidating gantry design

GE rolled out a new series of high-field MRI scanners in September that promises to increase patient comfort while fostering real-time interactive MRI applications. The new Signa MR/i series employs a new flared gantry design that shortens the length of the magnet bore, making the scanner less intimidating to claustrophobic patients, according to high-field marketing manager Brian Duchinsky.

Signa MR/i uses the same CX magnet employed in GE’s Signa Horizon LX series, and has the same patient bore width of 60 cm in diameter. The overall length of GE’s 1-tesla and 1.5-tesla magnet cartridge also remains the same, at 172 cm. But GE abandoned its old, two-stage flared opening scheme for a sculptured look that makes the entrance more inviting, Duchinsky said. By keeping the overall length unchanged, GE preserved magnet homogeneity specifications that were the main selling point of the Horizon LX line when the high-field, short-bore scanners were introduced last year (SCAN 8/20/97).

“We tightened up that critical dimension in the center that had a lot to do with the patient’s perception about how big the tube really is,” he said.

The “i” in MR/i stands for interactive, signifying improved image processing power. GE added a new reconstruction engine that increases the system’s standard reconstruction speed to 20 images per second. With optional hardware, the system’s performance increases to 50 images per second, Duchinsky said. The reconstruction engine works with GE’s standard operator console and normal, phased-array radio-frequency coils.

The console itself was upgraded in May to a Silicon Graphics Octane computer. A future, optional enhancement, based on research first performed with GE’s optimized cardiovascular MR platform, will further boost the scanner’s processing speed up to 150 images per second, Duchinsky said.

The emphasis on real-time applications reflects GE’s faith in real-time workups as an emerging trend in MR applications development. Several other companies are working on real-time applications products.

Cryogen conservation is another selling point of Signa MR/i. The 1-tesla and 1.5-tesla MR/i high-field models are equipped with new K-4 cryocooler technology that reduces cryogen refills to once every three years.