Advances at high field complement new offerings in open MR systems

Manufacturers unveiled a dizzying array of technologies designed to extend the clinical reach of MR, as they prepare for a clinical future where flexibility and productivity may determine success or failure. Most advances were being prepped for introduction on high-field scanners, but ways to migrate the technologies to open, mid-field systems were already apparent.

Spearheading MR’s clinical drive are imaging packages, most of them works-in-progress, designed for vascular imaging and diagnosing brain trauma and cardiac dysfunction. Intervention and surgical guidance are key adjuncts to these diagnostic offerings, although vendors voiced these themes cautiously, careful not to oversell applications that are only beginning to gain credibility. Supplementing these clinical thrusts were the inherent advantages of the short-bore and open designs through improved patient comfort. Fast-scanning protocols pay off with quicker scans and increased patient throughput.

Vendors with the biggest market shares had the most to offer and the widest range, with new coils, productivity enhancements, and advanced applications. Smaller competitors stressed value-oriented solutions or specialty products aimed at market niches.

Notably absent from the technical exhibit floor in MR were Caprius and Trex Medical. Caprius, developer of a dedicated MR mammography system, is attempting to sell its technology assets (SCAN 12/16/98). Trex, on the other hand, is embroiled in a legal battle with former supplier Intermagnetics General after their strategic alliance in low-field MR broke down (SCAN 11/25/98).

COHR/InnerVision

• COHR of Chatsworth, CA, and manufacturing partner InnerVision MRI of London, U.K., showcased the 0.17-tesla Ortho 8000 as a prelude to what they believe will be a surge of interest in extremity scanners. New features this year include a DICOM-compatible print capability and teleradiology software. Works-in-progress include positioning systems to support angulated studies.

Fonar

• The namesæand the paintæhave changed, but the equipment in Fonar’s booth was essentially the same in 1998 as in 1997. Fonar of Melville, NY, featured its Open Sky and Stand-Up MRI scanners, two works-in-progress systems built around the company’s 0.6-tesla vertical-field Quad 12000 system.
• Open Sky, essentially the same concept presented last year as OR 360, features a vertical-field electromagnet built into the ceiling and floor. The new name reflects murals painted on the walls, floor, and ceiling that are designed to make the system more patient-friendly. Open Sky is expected to be commercially available some time this year.
• Expected to accompany Open Sky to market this year will be Stand-Up MRI. First shown as a work-in-progress in 1996, this scanner is basically a Quad 12000 set on its side to allow patients to stand during examinations.

GE Medical Systems

• Real-time imaging bolstered by interactivity were the key points at the GE booth. Together, both techniques offer the potential for faster exams, improved patient comfort, better diagnostic information, and, ultimately, interventional and surgical guidance. GE engineers combined MR fluoroscopy with interactive control so operators can optimize the imaging sequence at virtually any point during an exam. Real-time interactive imaging could be most effective in cardiac, vascular, and bowel imaging, as well as kinematic studies of the joints, functional brain imaging, and MR-guided surgical/interventional imaging.
• A clinical highlight was cardiac imaging with Signa CV/i (cardiovascular interactive). System capabilities were exemplified by an impressive cine loop of the beating heart. Signa CV/i can capture a short-axis view of the left ventricle in less than 30 seconds.
• Signa MR/i (interactive), available at 1-tesla and 1.5-tesla field strengths, characterizes GE’s shift toward high-speed imaging, while paying homage to the industry-wide trend toward open-style systems. The new Signa is a makeover of GE’s short-bore Signa Horizon scanners, with a more compact casing, cleaner lines, and an advanced computer architecture to support the reconstruction of 20 to 50 images per second.
• Signa Profile/i extends the interactivity concept to an open design. A highlight was diffusion imaging, with a new head coil and high-performance 15-mtesla-per-meter gradients to support single-shot echo-planar imaging (EPI).

Hitachi Medical Systems America

• As the leading vendor of open MRI systems in the U.S., Hitachi sought to take the next logical step for this technology, featuring a work-in-progress interventional/intraoperative MR package for its 0.3-tesla Airis II system. Key components include an in-suite LCD monitor with articulating gantry arm mount, infrared cordless mouse control, special head and body coils with open access, directed gantry lighting, MR fluoroscopic pulse sequences, and video output for VCR recording.
• Hitachi’s version 5.0 software release, designed for MRP 7000 and Airis, offers enhancements including fast imaging and MR angiography.

Lunar/Esaote

• E-Scan is a dedicated open-style scanner that allows examination of all extremities, including the shoulder and legs up to the hip (SCAN 12/16/98). Supplied by Esaote to both Lunar and Siemens, the new system is built around a 0.2-tesla permanent magnet that can be sited in less than 200 square feet. E-Scan should begin shipping in the first quarter.
• A Web-based software package, called Network Package Plus, allows users of Esaote’s Artoscan dedicated extremity scanner to send images via DICOM, FTP, or e-mail.

Medison

• For the third consecutive RSNA meeting, Medison focused attention on high-field superconducting scanners operating at 1-tesla and 1.5-tesla field strengths. The systems, several of which are installed in clinical sites in Asia, are designed to be sited in less than 500 square feet. RSNA visitors could assess the capabilities of these machines only from booth panels, as the Korean company chose not to bring the heavy iron to the show.

Philips Medical Systems

• Cardiac MR was a focal point for Philips, which highlighted its Gyroscan-CV dedicated cardiac scanner. Frame rates of up to 40 images per second are possible with work-in-progress technologies, including the simultaneous use of six coils to acquire data; advanced computing technology that promises 240 reconstructions per second; and navigator technology that allows respiratory gating and real-time correction of slice positions.
• The company’s MobiTtrak system, featured at the 1996 RSNA conference as a work-in-progress, was the industry’s first automated peripheral vascular angiography technology for MR. Images are acquired in three steps of the table through the Gyroscan MR magnet, covering the aorta to the feet.
• Philips’ new CompactPlus magnet design is the latest result of more than a decade of work by Philips engineers in building compact MR systems. This newest version covers offerings at 0.5-tesla, 1-tesla, and 1.5-tesla and is compatible with MobiTrak-based MRA, as well as advanced techniques including functional brain imaging.

Picker International

• The Cleveland company introduced Outlook Proview. The open system, essentially an upgraded version of last year’s 0.23-tesla Outlook, is based on Windows NT. The scanner sports 16-mtesla/m peak amplitude and features a detachable couch, 18-inch patient gap, and side-first patient entry.
• A comprehensive hardware and software upgrade package, called Via Technology, offers compact gradient amplifiers and a new 500-MHz workstation for Picker’s 1.5-tesla Eclipse, 1-tesla Polaris and 0.5-tesla Apollo scanners. The package offers parallel processing capabilities and a redesign of key time-critical processes that together promise to increase patient throughput about 35% over previous technologies. Also included is a stroke assessment package based on FDA-cleared analysis algorithms that address perfusion and diffusion brain imaging.

Shimadzu Medical Systems

• Shimadzu’s Magnex Epios series, operating at 1.5-tesla, 1-tesla, and 0.5-tesla field strengths, was highlighted as a cost-effective, value-oriented product line, featuring image acquisitions up to a 1024 x 1024 matrix and image reconstruction as fast as 0.2 seconds per image. Shown at the 1997 RSNA meeting as a work-in-progress, the Epios line will begin shipping in the U.S. this year, first as an upgrade to the installed base of Magnex users and later as complete new units. A major difference is a 20-mtesla-gradient coil, which will allow longer fast spin-echo sequences and single-shot EPI.

Siemens Medical Systems

• Interactive capabilities on the high-field 1-tesla Harmony and 1.5-tesla Symphony scanners were positioned as a means for improving productivity. Siemens’ interactive technologies, utilizing MR fluoroscopy, are designed to reduce exam times by not only allowing improved patient positioning, but also enabling clinicians to make diagnoses on the fly. Fast-scanning technologies were leveraged to allow advanced clinical applications, including stroke assessment and cardiac imaging.
• The Open Viva open-style scanner was optimized for intraoperative procedures. A key addition is a new table that swings out, allowing surgeons to operate at the 0.5-mtesla fringe field and allowing 360 access to patients.
• A contrast-tracking system, based on peripheral coils compatible with Harmony and Symphony, allows peripheral angiography. A three-step moving table makes possible coverage from the abdomen to the feet.
• Along with Lunar and Esaote, Siemens introduced a new extremity scanner, although the German vendor calls its version Magnetom Jazz. A specialized interface and teleradiology capability distinguishes Jazz from the dedicated extremity scanner supplied by Esaote to Lunar. The interface matches that used on Siemens’ Magnetom MR product line.

Toshiba America Medical Systems

• Enhancements for Toshiba’s Opart cryogen-free open magnet include new work-in-progress software supporting faster MR fluoro and gated angiography with thinner and faster 2-D time-of-flight sequences. The package also enables more robust maximum intensity projection (MIP), gapless 2-D slices, curved multiplanar reconstruction, and true multi-angle oblique and breast imaging protocols. Also unveiled was the Performance Plus option, featuring improved advanced gradient compensation control (AGCC), water-fat separation, and echo mapping.
• Also highlighted was a dual breast coil that allows both breasts to be scanned bilaterally in a linear mode, or each breast to be scanned individually in quadrature mode. The coil is designed to be used in conjunction with Toshiba’s water-fat imaging sequence.