GE plans mid-field Signa offering

GE Medical Systems has applied for Food and Drug Administrationmarket approval of a 0.5-tesla version of its high-end Signa MRIsystem. The vendor hopes to receive the go-ahead for U.S. salesby next month.

The 0.5-tesla Signa will fill a gap between GE's 0.5-teslaMR Max and the 1.5-tesla Signa Advantage system, said Ronald J.Kokot, MR general manager.

"We will be able to cover more price points and satisfysome customers we haven't been able to satisfy before," Kokotsaid. "MRI customers have been looking for expanded clinicalutility at mid-field."

The 0.5-tesla Signa offers the computer horsepower and clinicalhardware and software of the high-field Signa but with a mid-fieldmagnet similar to the MR Max. Both mid-field systems will be soldand upgraded as separate products. Because of its higher clinicalutility, however, the mid-field Signa will cost more than theMR Max, he said.

GE is readying its version 5.5 upgrade for the MR Max, Kokotsaid. This will provide improved gradients and an expanded field-of-view,among other features. GE is also continuing to develop an MR angiographypackage for the Max. The 0.5-tesla Signa will be equipped withMRA, he said.

The high-field Signa will offer superior image quality at fasterscan times than the mid-field version. Some applications, suchas MR spectroscopy, will be available only on the high-field systembecause of physical limitations at lower field strengths. Butmost Signa high-field applications will be easily transferredto mid-field, he said.

"Our plan is to offer the same commitment to state-of-the-artfeatures at mid-field that we offer with the 1.5-tesla Signa,within the limitations of physics," he said.

The importance of MRI acquisition time in determining patientthroughput is declining as advances occur in fast imaging techniques,Kokot said. Three years ago, patient handling amounted to about20% of the total time of imaging procedures. In two years, patienthandling should make up 60% of the average exam time as acquisitionaccelerates, he predicted.

Since the mid-field Signa's magnet is similar to that of theMR Max, it will have similar shielding advantages in fixed andmobile installations, he said.

Reimbursement pressures and continued certificate-of-need (CON)price limitations on magnet purchases are increasing the pressurefor low-cost MRI, Kokot said. Additionally, diffusion of MRI technologyamong U.S. hospitals has prompted more low-throughput customersto consider MRI purchases, he said.

"A greater percentage of customers today question thesize of their patient pool. The are not convinced they can keepa 1.5-tesla Signa (busy), given their geographic areas, and theyare concerned about the risk of spending that kind of money."