MR enhancements focus on power and patient comfort

January 10, 2005

The emphasis this year at high field was on speed and enhanced clinical capabilities, particularly for brain and cardiac imaging. But patient comfort exerted more than its usual influence with the appearance of new types of open systems.

The emphasis this year at high field was on speed and enhanced clinical capabilities, particularly for brain and cardiac imaging. But patient comfort exerted more than its usual influence with the appearance of new types of open systems.

Open scanning has long been overshadowed by high-profile advances in 1.5T and 3T, but innovative developments shown this year on the RSNA exhibit floor forecast a brighter 2005. The world's first commercial 1T open scanner from Philips appeared, as well as a dedicated musculoskeletal imaging system from Esaote that rotates the patient from lying down to standing.

Engineers working on high-field systems contributed as well. Parallel imaging developments by Siemens and an enhanced data pipeline from GE marked technological growth at the higher fields.

Esaote

This member of the Bracco family of companies unveiled its G-Scan, a compact open MR that can image the spines of patients lying down or standing up, as the table and magnets rotate from a horizontal to a vertical position. G-Scan, which addresses musculoskeletal imaging, completes a portfolio that includes two scanners dedicated to extremity scanning: E-Scan XQ and C-Scan.

  • G-Scan's unique tilting gantry enables what the company has branded "Weight Bearing MRI" to facilitate musculoskeletal applications, particularly of the spine. The permanent magnet 0.25T system requires just 20 square meters (210 sq. ft.) for installation. The system will be sold first in Europe, although the company has obtained FDA clearance.

Fonar

Stand-Up MRI changed names. The new moniker for Fonar's 0.6T C-shaped open, turned on its side, is Upright MRI. The reasons, according to the company, were to better represent the technology and the clinical value of upright imaging and to enhance sales and marketing initiatives by creating brand awareness.

  • Cine cardiac images of a standing patient were displayed. Fonar chief Dr. Raymond Damadian asserted that physicians evaluating cardiac patients with heart failure "would prefer to see the heart performing against its normal physiological uphill load rather than in the lying down position, where the blood is practically running downhill."

GE Healthcare

The emphasis, as in past years, was on clinical capabilities, particularly how an improved data pipeline could expedite their adoption and utilization. Opportunities in brain, breast, and vascular imaging were described in technological terms linked to Excite HD (high definition). ExAblate 2000, an ultrasound-based therapy system designed for use with MR guidance, debuted commercially.

  • Excite HD supports growth of clinical applications through extension of data acquisition in increments of 16 channels. The data pipeline is compatible with 1.5T and 3T. Excite HD is designed to support 32-, 48-, and 64-channel coils, as they become available. The company launched a 32-element peripheral vascular coil that supports imaging of the lower leg and foot. HD MR may prove especially useful in handling patients who present unique scanning challenges due to their tendency to move uncontrollably, such as pediatric and Parkinson's patients.

  • Enhanced acquisition electronics balances the number of receivers to array processors and number of elements in the coil. Improved gradients focus on fidelity and repeatability of the wave form.

  • ExAblate 2000's cupola-like ultrasound device, built into the patient table of GE's 1.5T scanner, targets uterine fibroid lesions, using MR images for guidance and real-time MR thermometry to monitor ablative effects. Its developer, InSightec, was founded as a joint venture between GE and Elbit Medical Imaging (EMI), an Israeli investment and holding company. Shares in the company are currently split between EMI (54%) and GE (20%), with InSightec employees holding the remainder.

Hitachi Medical Systems America

This pioneer of open MR continued to enhance its midfield Airis platform.

  • Upgrades to Airis Elite were announced for the Airis and Airis II installed base. The Elite configuration, Hitachi's latest version of its 0.3T permanent magnet system, began shipping as a turnkey product about a year ago. The Airis Elite includes several sequences not available on the Airis II, including radio-frequency fat saturation, single-shot diffusion-weighted imaging, and parallel imaging.

  • 0.7T Altair offers cardiac imaging using parallel imaging and advanced imaging sequences. The upgrades were shown at last year's RSNA meeting as works-in-progress.

ONI Medical Systems

The developer of the 1T dedicated extremity scanner, OrthOne, demonstrated software and hardware enhancements.

  • An intermediate size RF coil with a diameter of 160 mm joins the other two OrthOne RF coils with diameters of 123 mm and 180 mm. The new coil adds flexibility in fitting patients' extremities so as to achieve better signal-to-noise.

  • Computing upgrades include migration from Windows NT to XP and from Pentium 3 to Pentium 4.

Philips

The portfolio includes Panorama 0.23T and 0.6T open MRs, as well as the cylindrical Intera 3T and Achieva 1.5T. Achieva can be configured for mobile or fixed use. Customized versions are available for cardiovascular and interventional applications. This year the high-field open Panorama 1.0T evolved from an engineering curiosity, where it had stalled since 1999, into a commercial product.

  • Panorama 1.0T debuted as a deliverable system. Its first commercial site was installed in October. The actively shielded vertical-field superconducting magnet comes with one gradient set offering an amplitude of 26 mT/m (milliTesla per meter) and slew rate of 80 mT/m/sec. The company claims that image quality and scan times with the system are comparable to those of 1.5T systems. Routine deliveries are scheduled for early 2005, and 10 sites are expected to be in place by midyear.

  • Panorama 0.6T interventional system, a work-in-progress, is being groomed for use in biopsies and therapies involving drainage or nerve root infiltration into the spine. The first installation is scheduled for early in the year at Turku University Central Hospital in Turku, Finland.

  • A second set of gradients for the Intera 3T operate at 40 mT/m with a slew rate of 120 mT/m/sec. The standard set runs at 80 mT/m with a slew rate of 200 mT/m/sec.

Siemens

New patient-oriented systems and high-end coil technology were key. Ultrashort-bore Espree promised to energize the debate over the definition of "open" MR. Magnetom C! appeared as Siemens' approach to the premium low-field MR market. Total Imaging Matrix (TIM) was enhanced, offering new capabilities, including extended parallel imaging.

  • TIM body coil technology was adapted for use on the company's 3T whole-body Trio scanner. The surface coil technology, introduced at last year's RSNA meeting, combines up to 76 seamlessly integrated coil elements with as many as 32 RF channels.

  • iPAT2 exploits the company's parallel acquisition technology, allowing data acquisition in 3D space. The result is increased acceleration, achieving multiples of eight and sometimes 12, according to the company.

  • Espree, an ultracompact cylindrical 1.5T scanner with a CT-like opening, is being positioned as the forerunner of a new class of MR - an open-bore scanner with a 70-cm diameter. Production is scheduled to begin in February.

  • Magnetom C!, a clam-shaped MR, added punch to the Siemens portfolio, providing a 0.35T permanent magnet alongside the company's 0.2T Concerto.

Toshiba

The company last year released the Ultra version of its 0.35T Opart platform, as well as an ultracompact 1.5T system, Vantage. The base configuration of Toshiba's high-field system includes AGV gradients operating at an amplitude of 30 mT/m and a slew rate of 50 mT/m/sec. The high-performance Vantage XGV gradients operate at 30 mT/m gradient strength with a slew rate of 130 mT/m/sec.

  • New Vantage gradients were introduced to serve as an intermediate alternative. MGV features an amplitude of 30 mT/m and a slew rate of 86 mT/m/sec. Work-in-progress ZGV will have an amplitude of 33 mT/m and a slew rate of 200 mT/m/sec.

  • Ultra's Version 5.0 software includes new pulse sequences: SuperFASE, Steady State Two Echoes for high-contrast imaging, Steady State T2 for conducting heavily weighted T2 images, Sliding Slab for enhanced 3D time-of-flight brain MR angiography, Variable No Phase Wrap, Line Scan Diffusion to complement single-shot echo-planar imaging; and Swirl Encoding to reduce the flow and motion artifacts.

  • A breast biopsy package features a new breast coil and MR fluoroscopy software with in-room monitor. Cardiac analysis is also available using software from Confirma.

  • Diffusion-weighted body imaging visualizes inflammatory conditions.

  • A "chimney" coil allows knee scanning, as well as upright foot scanning with toes shunted into a rectangular chute at the top of the coil.

  • The "floating on a cloud" sky blue and white paint job creates a more soothing atmosphere for $5000.

  • A trade-in/upgrade package was developed, under which the company will accept any MR system as trade-in for Ultra. Net cost to the customer will be under a half million dollars.