Shimadzu targets 1-tesla MRI niche

Shimadzu Medical Systems is beefing up its 1-tesla MRI lineupwith two new scanners to be unveiled at the Radiological Societyof North America meeting this month. The new systems spearheada renaming of the Japanese vendor's MRI product line, accordingto Donald Karle, marketing manager of CT and MRI.

Shimadzu has shed the SMT preface for its scanners in favorof Magnex, a term already in use in Japan, Karle said. The newproduct line will be highlighted by Magnex 100/HP, a 1-tesla scannerto be shown at the RSNA conference as a works-in-progress.

Magnex 100/HP will be Shimadzu's flagship MRI scanner in theU.S. market. The vendor added actively shielded gradients to thelarge, one-meter-bore magnet in the 100/HP unit. Actively shieldedgradients are commonly used to reduce eddy currents produced bysystems with small magnet bores. Installing them on a large-boremagnet reduces eddy currents and improves the overall image qualityof the fast spin-echo sequences, Karle said.

Using Shimadzu's fast inversion recovery protocol, Magnex 100/HPcan perform a complete fast spin-echo study with T1 imaging, acquiring12 to 16 images during a scan.

"While most companies stress their fast spin-echo programsfor T2 imaging, we can do a complete clinical study doing fastT1," Karle said. "We can do fast T2, fast dual contrastand fast T1 imaging all with spin echo. This is something we believesets us apart."

By using T1 imaging for anatomical landmarking and T2 imagingto pinpoint pathology, radiologists will be able to conduct acomplete brain examination in eight minutes, he said.

Several of Shimadzu's fast scanning packages will be standardon Magnex 100/HP, such as RISE (fast spin echo), SMASH (turbofield echo) and magnetization transfer contrast MR angiography.

Shimadzu will provide an upgrade path to the Magnex 100/HPfrom the company's existing 1-tesla offering, the SMT-100X, whichwill be phased out. A full upgrade would cost about $400,000,Karle said. Shimadzu expects FDA marketing clearance of Magnex100/HP by December.

Shimadzu's second MRI scanner in the Magnex series is Magnex100, intended to open up a second price point in the 1-tesla niche.The list price of Magnex 100 is $1.6 million, $200,000 less thanMagnex 100/HP. Shimadzu will show images from the works-in-progressscanner at its RSNA booth.

While Magnex 100 has many of the same features of its priciercousin, the scanner in its basic configuration does not have activelyshielded gradients or RISE, SMASH and MTC MRA. Those featuresare optional, Karle said.

Shimadzu has also beefed up the computer system and image processorof the Magnex series, according to Karle.

Shimadzu's development of the Magnex scanners is further validationof the growing popularity of 1-tesla scanners as a compromisebetween horsepower and economy. GE Medical Systems jumped on the1-tesla bandwagon when it introduced the Signa Advantage 1T earlierthis year (SCAN 7/28/93).

"The 1-tesla system is a good balancing act between theneed for high resolution and high throughput with similar imagequality and speed as the 1.5-tesla magnets," Karle said."If you look back, Picker, Shimadzu and Siemens were theonly companies that believed in the 1-tesla level as the bestcompromise between price, speed and image quality."

Shimadzu will also unveil a new CT scanner, SCT-4800T. Theunit is intended to be a cost-effective system in the $500,000range. Shimadzu has designed the scanner's x-ray generator topower both the CT scanner and a radiographic room. A hospitalcan locate the CT room adjacent to the radiographic room, or aradiographic system such as an overhead crane device can be locatedwithin the CT suite, enabling a single operator to conduct bothprocedures.

"We believe it is the first system designed specificallyto operate two separate rooms," Karle said. "If patientscome in in a trauma situation, they can be brought in to the singleroom, and once they are placed on the CT table they don't haveto be moved again."

Shimadzu has filed for Food and Drug Administration 510(k)clearance for the system and expects to begin shipping in thespring of 1994.