Toshiba’s foray into high-field imaging has taken a giant leap forward with the release of its Vantage ZGV, a 1.5T system outfitted with coils and software designed to return performance at the same level as a 3T system, according to the chief MR executive of the company’s U.S. arm.
Toshiba's foray into high-field imaging has taken a giant leap forward with the release of its Vantage ZGV, a 1.5T system outfitted with coils and software designed to return performance at the same level as a 3T system, according to the chief MR executive of the company's U.S. arm.
Brain images created using the Vantage ZGV, which cleared the FDA in January, show exquisite detail. But the extraordinary imagery does not stop at the neck. Cardiac images acquired on the ZGV demonstrate tiny vessels that spring from the major coronaries.
A workstation introduced March 11 at the American College of Cardiology conference processes MR cardiac data with such detail that the information rivals what can be obtained from conventional modalities, according to Bob Giegerich, director of the MR business unit at Toshiba America.
The workstation, which is pending FDA clearance, processes MR angiographic data acquired with the Vantage ZGV, using software that does not require contrast-enhanced data. Specialized algorithms correct for motion artifacts in real-time.
"We are on the verge of having a complete cardiac panel," Giegerich said. "With this, MR will replace everything - nuclear medicine, ultrasound, and cardiac cath."
Gadolinium-based studies, performed on the Vantage ZGV and processed on the new workstation, pick up scars in the myocardium so small they may escape detection with thallium studies using conventional gamma cameras, he said. Delayed enhancement data, also obtained with contrast, might help identify patients who will benefit from revascularization following myocardial infarction.
Giegerich touts the Vantage ZGV, which began routine shipping only in the last several weeks, as a premium performance high-field system, delivering performance in some cases comparable to that of 3T scanners.
Until three years ago, Toshiba's claim to fame in MR was its 0.35T Opart, a decade-old superconducting open system. Over the years, Toshiba engineers have brushed up its clinical performance with new coils and software, creating a premium version called Ultra, but that hasn't stopped its market presence from diminishing with the waning demand for midfield systems in the U.S.
Toshiba hopes to make up for lost fortunes with the success of Vantage, launched commercially in 2003. Giegerich credits development of the latest version to a partnership between U.S. and Japanese scientists.
About a dozen scientists in the U.S. subsidiary of Toshiba and another 150 engineers at Toshiba Headquarters in Nasu, Japan, collaborated on the development of the Vantage ZGV, which offers a gradient strength of 33 mT/m and a slew rate of 200 T/m/sec. Field upgrades to the ZGV are available to current Vantage users.
The newly minted product tops the Vantage family, which is built on an ultrashort magnet measuring 140 cm long. Other family members offer a linear 30 mT/m gradient strength with a slew rate of 50 T/m/sec (Vantage AGV), 86 T/m/sec (Vantage MGV) or 130 T/m/sec (Vantage XGV).
Vantage ZGV offers the "Z" gradient coil, the fundamental technology that gives the system it 3T-like zip, according to Giegerich. Engineers at MR Instruments hope to boost the power further, as they adapt their own technology to create an innovative head coil, dubbed T3 by Toshiba, to support head images that Giegerich says will rival those obtained using 3T MRs.
"We want to focus on the head because that is where 3T has always claimed it is better than 1.5T," he said. "By proving we can produce 3T images using this combination of ZGV and a head coil, we will refute that."
The proprietary technology underlying the coil was first developed by MR Instruments for use on systems operating at 3T and above. At the 2005 RSNA meeting, the Minneapolis-based company launched a Cheetah line of 3T coils for Siemens and GE 3T systems.
The products transmit and receive MR signals, using separate electronic circuits distributed throughout the coils. The efficient design generates a stronger signal, according to MR Instruments.
The head coil being built for Toshiba will work on the company's latest version of Vantage, which is equally at home at the high end of cardiac imaging. Toshiba's cardiac MR package produces images on a par with the gold standard of cardiac imaging.
"We call it our pseudo-spider-view - coronaries floating in space with a shadow of the heart behind them," Giegerich said. "In cardiac cath, that is the money shot. It's the hardest shot to do, because you are going through the most beef, but it's a snap with MR."
Like the head shots, images of the coronaries are done on the Vantage ZGV, which the Toshiba executive refers to as "Mister Z." The power underlying these images comes from the slew rate, made possible by the Z gradient, as well as from specialized software.
Giegerich has a knack for coming up with monikers and acronyms that have a familiar ring. The company's proprietary contrast-free imaging technologies bear familiar acronyms: Fresh Blood Imaging (FBI) and Contrast Improved Angiography (CIA). Developed in 1998, FBI is the technology platform for CIA. Supporting advanced applications is the Mach 8 processor, capable of reconstructing 1230 images per second, three times faster than its predecessor.
These technologies will keep Toshiba in the high-field game until its engineers come out with a 3T system, which Giegerich said they are working on now.
"We will have it when we can add value to the marketplace," he said.