GE has unveiled a new 3T scanner, the Signa MR750, the first in a new generation of Signa scanners designed to handle the toughest imaging cases with minimal effort. More powerful gradients, increased anatomical coverage, enhanced parallel imaging, and a user interface that simplifies routine as well as academically challenging protocols promise to allow 3T to reach its clinical potential, said Jim Davis, GE vice president and general manager of global MR business.
"The feedback we've gotten in MR has been that the complexity of systems is constraining the use of MR across many clinical applications today," Davis said. "This next generation, the MR750, is really going to be much simpler and more intuitive to speed up exams and make the scanner easier to use and, thus, enable the scanner to be used more broadly."
Testing at Stanford University, the University of Wisconsin-Madison, and in engineering bays at the company's MR headquarters outside Milwaukee have shown that the MR750 can cut the time needed for peripheral vascular exams to six minutes and breast exams to four. Real-time cardiac scan times can drop as much as 30%.
About a week before the ISMRM meeting, GE received FDA clearance to market the MR750. Beta testing will continue for the next couple months, as the company ramps up for a scheduled commercial release at the end of summer.
Parallel imaging algorithms, dubbed ARC (autocalibrating reconstruction for Cartesian), are coupled with high-definition coils to reduce scan time and help keep specific absorption rate (SAR) in check. This is especially critical when doing challenging exams, such as those of the abdomen.
Lava-Ideal, a dual-echo application, boosts productivity by acquiring the data to output four image contrasts — in-phase, opposed-phase, water only, and fat only — from a single scan. This reduces the number of scans per exam, allowing complete acquisition in a single breath-hold.
An advanced motion artifact application, Propeller 2.0, is optimized for brain imaging. Its "No Phase Wrap" technique virtually eliminates motion artifact in the sagittal, coronal, axial, and oblique planes, according to GE.
A combination of two sequences, Vibrant and Ideal, synthesizes water and fat images during breast imaging. Ultrashort in- and out-of-phase echoes keep scan times comparable to single-echo acquisitions despite acquiring about double the amount of data.
Under the hood driving these applications is a whole-body gradient system that delivers 50 mT/m amplitude and 200 T/m/s slew rate, a notch above the 45 mT/m amplitude and 150 T/m/s slew coming from the current Signa HDx 3.0T. The net is a 60% increase in resolution. The MR750's 48-cm field-of-view provides a similar boost in anatomical coverage.
A new high-bandwidth optical RF receiver reduces noise and an 80-MHz bandwidth and fiber optics system maximizes signal intensity to provide clean, crisp images drawn from data acquired with high-density surface coils. A new thermal management system keeps SAR in check, increasing scan efficiency 17%.
The receive electronics are packaged in 16-channel modules mounted on the side of the MR750. The system can accommodate eight such modules, totaling 128 channels.
The power of the gradients, efficiency of the user interface, and scalability of the system speak as much to what the MR750 can do now as to what it will be able do in the future, Davis said.
"The platform has a lot of runway left," he said.
