Philips hits the highway with big ironon tour with 1.5-tesla mobile MRI unit

NT Mobile scanner travels fully ramped up

Philips Medical Systems hopes to inject some life into the mobileMRI industry by releasing a transportable version of its 1.5-teslaGyroscan ACS-NT scanner. The magnet is unique among 1.5-teslasystems in that it is capable of traveling at field, reducingset-up time to a matter of minutes.

Philips, of Shelton, CT, sent a 1.5-tesla NT Mobile on tourlast month to showcase its capabilities. The scanner logged some7400 miles on a tour that lasted six weeks, and traveled fullyramped up the entire time, according to Joe Nagle, product managerfor mobile MRI.

The development of mobile 1.5-tesla MRI has been hampered becausethe magnetic fields of previous 1.5-tesla mobile scanners mustbe ramped down while traveling. This avoids interference withmoving metal objects in the environment, which can disrupt thehomogeneity of the scanner's magnetic field. It then takes severalhours to ramp up the magnet once it has reached its destination.

In 1993 Philips debuted the NT scanners, which were notablefor their compact size and light weight (SCAN 12/29/93). IntermagneticsGeneral supplied Philips with the compact magnets, but Philipsalso developed technology for the line that provides a means ofprimary field compensation, ensuring that the homogeneity of themagnet stays constant even if there are moving metal objects nearby.The technology makes siting the NT scanners easier in stationarysettings but provides even greater advantages for mobile MRI.

"The system is much less sensitive to moving ferric objects,such as automobiles and trucks," Nagle said. "It's notas sensitive as previous magnets have been."

NT Mobile is identical to a standard 1.5-tesla NT and can performall the sequences the stationary magnet is capable of, including1024 x 1024 imaging, echo-planar imaging and GRASE. The only applicationit does not support is spectroscopy, due primarily to logisticalissues such as reimbursement.

Philips decided to put NT Mobile on tour to dispel doubts about1.5-tesla mobile imaging. Past efforts have had disappointingresults, according to Chris Farr, director of marketing for MRI.

"In the past one of the big companies had a 1.5-teslamobile. It was a disaster," Farr said. "What we wantedto show was not only that this machine was truly mobile, but thatthere was no compromise on capabilities or performance."

On NT Mobile's summer tour, Philips employed a truck manufacturedby Calumet Coach of Calumet City, IL. The system can also be configuredin mobile vans manufactured by Ellis and Watts of Batavia, OH.Additional shielding in the magnet's trailer confines the magnet'sfive-gauss line entirely within the trailer walls.

Philips also placed a 3M DryView 8700 dry laser printer inthe mobile van. The printer obviated the need to have film sentoutside the van for developing, making mobile imaging even morepractical.

Philips believes NT Mobile will help revive the mobile imagingsegment, which has experienced a shakeout in recent years as manysmaller hospitals once on mobile routes acquire their own scanners.Many of these hospitals have acquired mid-field magnets to avoidthe cost of 1.5-tesla systems, but still have a need for high-fieldimaging.

"What has happened in MRI is that a 0.5-tesla machinecan be afforded by even quite small community hospitals,"Farr said. "This 1.5-telsa scanner is bringing a level oftechnology to these hospitals that there is absolutely no waythey could afford on their own."

Philips is in discussions with mobile firms, many of whom needto replace older mid-field MRI scanners in their fleets and wouldwelcome the opportunity to offer 1.5-tesla scanning. The companybelieves it will ship as many as 10 NT Mobiles by the end of theyear.

Other potential customers include large hospital chains thathave purchased smaller suburban hospitals and would rather setup a mobile route between the smaller hospitals than install anew 1.5-tesla scanner in each facility, Farr said.

"What this provides them with is the ability to take thesame kind of technology as they have at their home base and offerit as an outreach service," Farr said.