MR industry focuses on innovation within reach of technology

December 25, 2002

Vendors are treading lightly on the ground they have already plowed. Unveilings and works-in-progress shown at the RSNA meeting were the offspring of mature technologies rather than breakthroughs. The reason may be that no major innovations are

Vendors are treading lightly on the ground they have already plowed. Unveilings and works-in-progress shown at the RSNA meeting were the offspring of mature technologies rather than breakthroughs. The reason may be that no major innovations are needed.

Cardiologic and oncologic applications continue to tantalize, but the means for achieving them are being found in iterative improvements, mostly for high field. A few are being designed, however, for open scanners operating at 0.7T and below. Leading these innovations is parallel imaging, which continues to advance the capabilities of high-field cylindrical systems and potentially some open scanners.

Enhanced coils, gradients, and software to boost the performance of 1.5T systems are as much as the industry needs or customers want. Whole-body 3T scanners may indeed be the successor to 1.5T as the benchmark for high-performance imaging, but it will likely take them a while. Vendors are talking down expectations about how fast or in what directions these systems will evolve. The apparent inevitability of 3T systems' dominance at the high end of clinical applications was enough, however, to make at least one major vendor extend its MR family to the 7T level.

Gone from sight are the engineering wonders--the 1T opens--that vendors recently had predicted were right around the corner. Economic considerations have pushed these into the background as clinical prototypes have proved too expensive to mass produce.

Esaote

An early developer of specialty MR scanners, Esaote continues to promote and develop its line of products dedicated to orthopedic applications. Nearly a decade ago, the company assigned U.S. distribution rights for its Artoscan extremity scanner to Lunar, a vendor known at the time primarily for bone densitometers. Lunar has since been acquired by GE Medical Systems, but the agreement to distribute extremity scanners lives on, with Esaote selling its MR products outside the U.S. The Artoscan has become C-Scan, which has been joined by E-Scan, an open-style dedicated extremity scanner.

  • E-Scan evolved into E-Scan XQ on the heels of a software upgrade that changed the operating system from Unix to Windows 2000. Software improvements reportedly boost signal to noise by 35%.
  • C-Scan software improvements have been initiated to improve image quality.

Fonar

A pioneer of clinical MR scanners, Fonar has stood the test of time, albeit with the help of attorneys specializing in patent law. The company's huge civil suit victory over GE and consequent out-of-court settlements with other MR vendors in the 1990s infused the company with the cash it needed to keep going long enough to become a substantial vendor of modern open MR scanners. Its Stand-Up MRI, which allows patients to be scanned standing or sitting, is driving interest among customers and rebuilding credibility for the company.

  • A new stylized version of the Stand-Up MRI graced the Fonar exhibit. The company maintained the character of the product but swept back its external contours to form a sleek new package that slowly rotated on a turntable at the entrance to the Fonar booth. The company hopes the new styling will boost appeal beyond its current level of 31 sales, 12 of which are in operation.
  • Newly developed Quadrature RF receiver coils were featured along with clinical images showing how they improve quality.

GE Medical Systems

GE was in MR when the modality was little more than technological wizardry. The company dominated the MR market in the mid-1980s and has continued to be the undisputed global market leader, particularly strong in the U.S. The company maintains a comprehensive portfolio, including cylindrical whole-body scanners available at 3T, 1.5T, and 1T as well as open systems at 0.35 (Ovation) and 0.7T (OpenSpeed).

  • Signa Infinity 3T, featuring a compact magnet, made its debut. The product, which is expected to begin shipping in 2003, will evolve to include twin gradients and eventually Excite technology. The compact 3T product will supplement GE's installed base of 78 bulkier 3T systems, 63 of which are in whole-body configurations.
  • Excite, a redesign of the imaging pipeline for high-performance scanners, made its first RSNA appearance. The upgrade, introduced in May, integrates the multiple components that transmit, receive, and process MR information.
  • A software package cleared by the FDA prior to the RSNA meeting fuses 3D x-ray and MR data sets to help physicians visualize brain tissue and blood vessels.
  • Two sequences were introduced for OpenSpeed: diffusion-weighted echo-planar imaging for acute stroke detection and FIESTA, a fast high-resolution imaging sequence.
  • Ovation was updated with a 72-inch flexible body coil that was designed to provide 30% better signal to noise, promising optimized scan time and resolution as well as a faster computer with increased memory for image storage.

Hitachi Medical Systems of America

The MR recession of the mid-1990s may be ancient history, but Hitachi's role in leading the industry out of it remains fresh. Hitachi's popularization of open scanners rekindled MR equipment sales seven years ago and established the company as the undisputed leader in the open marketplace. Hitachi has built on this legacy, updating its Airis II line of midfield open scanners, and in 2000 introducing Altaire, a 0.7T open product.

  • Three pulse sequences were introduced for the Airis II and Altaire: driven equilibrium fast spin-echo, balanced SARGE, and diffusion-weighted echo-planar imaging with fat suppression.
  • The Altaire High-Field Performance package provides an Enhanced DualQuad RF upgrade, which includes an integrated transmit/receive body coil and QD receive coils that operate as a multiple array. These coils will support MR applications now in development, including peripheral vascular, neurovascular, and breast imaging, as well as cardiac scanning.
  • RAPID (rapid acquisition through parallel imaging) sequences are being developed along with the necessary RF technology for integration on Altaire and, potentially, Airis II.
  • Preprogrammed radial multiplanar reconstruction on the Airis II provides faster, more efficient reformatting of acquired slices.
  • Multiplan/multiscan acquisition on the Airis II supports faster prescans and dynamic scanning.
  • An optional DICOM modality work list for Airis II improves communication between RIS and HIS from workstations.
  • A breast coil, now in development for both the Airis II and Altaire, maximizes the size of the opening to allow needle biopsy.

ONI

Dedicated extremity scanners have accounted for a modest number of sales each year but have failed to win mass acceptance. The reason, according to ONI, is that these systems have not been able to deliver image quality equivalent to that of high-field general-purpose MR scanners. ONI was founded on the idea that such image quality could be produced with relatively compact dedicated systems. The company's commercial release of such a scanner, OrthOne 1.0T, may test the validity of that idea.

  • Version 2.0 software enhancements streamline the OrthOne user interface, improve the transfer of images from the scanner to workstations, and refine pulse sequences and protocols to improve image quality.
  • Plans were discussed to develop the second in ONI's family of niche scanners, tentatively dedicated to brain scanning.

Philips Medical Systems

The integration of products designed by Marconi Medical Systems has provided Philips with the widest selection of MR scanners in the industry. Philips' family of cylindrical Intera MR scanners, with their compact footprint, has been buoyed by Marconi's emphasis on open scanners, namely its Panorama 0.6T Infinion HFO (high field open) and Panorama 0.23T low-field system. Although the company last year described the Marconi-designed ultracompact Infinion 1.5T as an "open" product, the system has been redefined as being in "a class of its own." Philips is reengineering its open high-field Panorama 1.0T in an effort to gain cost efficiencies that will help make the product economically viable. The company is examining new developments through luminary sites experimenting with hybrid systems that combine the Intera 1.5T with a Philips x-ray-based interventional system.

  • Intera 7T marks the growth of Philips' product line to ultra high field. The design of a 7T scanner is being standardized for an initial production run of 10 units. The first unit is slated for installation by mid-2004. Orders for half of the others are in hand. All are expected to be installed by the end of 2006.
  • Panorama 0.23T has been optimized as an MR simulator for oncology. Software for radiotherapy planning establishes the system as an alternative to the CT simulator for patients with selected malignancies, particularly prostate cancer.
  • Galaxy class gradients have been added in several varieties, from bottom to top: Pulsar, Stellar, Nova, Nova Dual (dual gradients), and Quasar. High-performance gradients will be particularly useful in advanced studies, such as diffusion tensor imaging to track nerve fibers in the brain and spinal cord.
  • RapidView, an advanced computing engine available on Philips MR products, reconstructs up to 860 images per second. Interactive imaging allows adjustments on the fly, which may be particularly useful in planning cardiac exams, performing MR-guided interventions, and conducting studies of the bowel.
  • The latest version of Philips proprietary parallel imaging technology SENSE (sensitivity encoding) boosts image acquisition by up to 600% over exams not using this method, according to the company. This shortens exam time, decreases motion artifacts, and increases throughput. This technology has been built into a new head coil that enables high-quality brain scans in 20 seconds.
  • A microscopy coil set enables small-field-of-view imaging for examining the skin, eyes, small joints, and superficial vessels.
  • A whole-body imaging package allows patients to be scanned from head to toe in less than 10 minutes. Such scanning might be used for comprehensive vascular screening or even as an alternative to nuclear medicine when mapping the body for cancer. The technology is an evolution of Philips' MobiTrack, which uses a moving table to sequentially reposition the patient in the MR field-of-view until an MR peripheral angiogram is complete. (MobiTrack technology was expanded this year to include up to five patient stations for data acquisition.)
  • SofTone technology reduces acoustic noise by more than 85%.

Siemens Medical Solutions

As one of the premier vendors of MR technology, Siemens has sought to build on established scanner platforms at all levels of performance, while integrating its Magnetom products with those of other digital modalities using its syngo standard user interface. Workflow, in the context of patient outcomes and improved healthcare, is the company's watchword.

  • Phoenix software allows clinicians to initiate a scan directly from images, transferring protocols for these images stored on a CD. With this capability, clinicians have the means readily available for duplicating a protocol or following a patient over time by performing the same study without having to reenter protocol parameters.
  • PACE technology offers motion control to optimize image quality. It is particularly useful for correcting respiratory artifacts.
  • iPAT (integrated parallel acquisition techniques) has evolved to reduce acquisition time by up to 75%, while maintaining image quality.
  • Inline Technology allows the immediate display of data sets and processing results. A color overlay assists in the reading and analysis of data maps.

Toshiba America Medical Systems

A seemingly ill-fated decision in the late 1980s to buy the MR division of Diasonics actually led to the salvation of Toshiba America as a vendor of MR systems in the U.S. The corporate acquisition failed to achieve its primary purpose: to provide an installed base of MR scanners for service revenues and future sales of Japanese-made scanners. It did, however, provide the engineering know-how to establish Toshiba as a major vendor of a premium performance midfield superconducting open system called Opart. Now the 0.35T Opart platform may serve as a launching pad for further growth in midfield imaging, as the company prepares to assume a larger role in high-field imaging.

  • Ultra is the next-generation Opart built around gradients that achieve an amplitude of 25 mT/m and slew rate of 100 T/m/sec. This combination supports advanced clinical applications, high-resolution imaging, and fast scanning that the company claims are comparable to those of high-field systems, while retaining Opart's open environment.
  • New imaging techniques available on Ultra include single-shot EPI diffusion, True SSFP, SuperFASE, and black blood MR angiography.
  • Excelart, Toshiba's 1.5 T offering, expanded into a family of products with different price points. The Excelart AG, XG, AG/S, and XG/S are differentiated primarily by gradients and subsystems that determine varying performance levels. AG has a gradient amplitude of 30 mT/m and a slew rate of 50 T/m/sec; XG has a gradient amplitude of 30 mT/m and a slew rate of 130 T/m/sec. The "S" (spin) configurations include Speeder, Toshiba's proprietary parallel imaging technology.
  • Speeder was commercially released. Equipped with 16-channel QD receiver coil, Speeder promises to triple scanning speed while producing images in any plane. A 3D interactive locator allows plane selection.
  • A 1.5T ultrashort-bore scanner was shown as a work-in-progress. The prototype, scheduled for commercial release late next year, is being designed around the same magnet provided by Oxford to Philips for its Infinion 1.5T ultracompact scanner. The new product could be positioned as the industry's most compact MR scanner. Although the magnet will have exactly the same dimensions as those in Philips Infinion 1.5T, the cowling surrounding it has been swept back to minimize the footprint.