MAGNETIC RESONANCE

Faster image reconstruction and improved system versatility serve as hot buttons at 1998 show

Real-time imaging powers MRI product launches

Open MRI, equipment replacement, and high-field product innovation are contributing to the boom. A big hit with consumers, open MRI composes 45% of all U.S. unit sales this year, according to vendors. High-field MRI sales also rose as providers began replacing their aging scanners.

Innovations have encouraged scanner trade-ins. New, short-bore 1- and 1.5-tesla products promise better throughput, improved clinical versatility, and less patient discomfort than older equipment. This year's product introductions will echo these themes.

WHAT TO LOOK FOR

Caprius. The company will feature a new workstation upgrade that allows physicians to review three-dimensional MRI digital images acquired by Aurora, its dedicated MRI breast imager.

Elscint. Everything is up in the air at Elscint since the Israeli company sold its MR, nuclear medicine, and CT product lines in September. The 1-tesla Prima 1TG, equipped with dual gradients, generates considerable interest, but potential purchasers will have to wait until the show to learn where the program stands.

Fonar. The company will feature progress on its OR-360 dedicated interventional suite as a commercial product.

GE. The Signa MR/i high-field series employs a new magnet configuration that reduces the length of the interior section of the bore from 148 to 70 cm. The bore's 60-cm diameter remains the same as GE's previous CX high-field magnet design.

The overall length of GE's 1- and 1.5-tesla magnet cartridge is still 172 cm, but GE abandoned its two-stage flared opening scheme for a sculptured look that makes the entrance more inviting. By keeping the overall length unchanged, GE preserved magnet homogeneity specifications that were its main selling point when Horizon LX, the company's first generation of high-field, short-bore products, was introduced last year. The standard HiSpeed and EchoSpeed gradient coils options available on the Signa MR/i are also unchanged.

The "i" in MR/i stands for interactive, signifying improved image processing power. GE added a new reconstruction engine that increases the system's standard reconstruction speed to 20 images per second. With optional hardware, the performance increases to 50 images per second.

Hitachi. Hitachi will feature enhancements to its 0.3-tesla Airis II and 1.5-tesla Stratis II scanners. Airis II gained Food and Drug Administration clearance this year. The first production model was installed in January at a dedicated interventional MRI suite adjacent to the surgery department at University Hospital in Cincinnati. Hitachi will highlight early investigational experience with the machine.

For Airis II customers, Hitachi will introduce a series of phased-array RF coils for head and neck, spine, and shoulder applications. Software upgrades for Stratis II will also be on view.

InnerVision. Designed to complement InnerVision's Ortho 8000 extremity scanner, a new workstation that combines image interpretation, archiving, and teleradiology will be shown as a work-in-progress.

Lunar/Esaote. Lunar will introduce Network Package Plus, an Internet-based communications software system for Artoscan M, the modular version of the 0.2-tesla extremity MRI scanner that was first shown at the 1997 conference. Network Package Plus creates a variety of networking capabilities. Controlled from an Artoscan standard operator console, it incorporates an Internet connection to transmit MR images and patient information described on the DICOM header to remote sites. The system formats data in Artoscan's proprietary format or in GIF formats for transmission.

Philips. For visitors who are unaware that Philips first introduced short-bore MRI products, the company will commemorate the 10th anniversary of its technology.

Philips will introduce Mobitrak, a unique moving-table angiography system. Mobitrak is designed specifically for dynamic contrast-enhanced MRA. It is especially valuable for peripheral vascular studies. Using a 3-D fast-field echo pulse sequence, Mobitrak can acquire contrast-enhanced, peripheral vascular studies covering the aortic bifurcation to the toes in four minutes.

Netview is a new Web-based communications system that allows referring physicians to download sample images of their patients' MRI studies.

Philips' works-in-progress include a new breast localization device that guides breast biopsies, a short TR and TE lung diffusion-imaging technique that helps find emboli and characterize the severity of emphysema, and a real-time interactive contrast and acquisition planning tool that illustrates the anatomical coverage defined by specific image parameters. In the cardiovascular arena, Philips will feature coronary artery imaging advancements in spiral scanning and imaging with dedicated blood pool contrast agents.

Picker. Picker will orchestrate the U.S. debut of its new, open-style Proview, the final component in a thorough product line renovation.

Proview's 18-inch patient gap, side-first patient entry, and detachable couch improve patient access.

A flat patient bed accommodates large patients and aids interventional applications. An optional second table, featuring vertical motion, enables technologists to position a patient and an RF coil before wheeling the table into the imaging suite. Proview's 0.23-tesla resistive magnet ramps up from cold start in less than six minutes.

Proview's gradient coils produce a minimum of 16 mtesla/m and ramp up to peak amplitude at the rate of 25 mtesla/m/sec. Proview is delivered with phased-array RF coils and a 433-MHz Microsoft Windows NT computer as standard equipment.

The exhibit will emphasize the initial clinical experience with minimally invasive surgeries performed with a Picker open MRI scanner and the company's ViewPoint surgical guidance system.

Enhancements to Polaris and Eclipse include a new 500-MHz host computer and optional software that boosts the reconstruction rate to 30 images per second.

Picker will also introduce Resolution-Aided Matrix (RAM), a processing technique that diminishes the trade-off between resolution and scan times. This general-purpose technique can optimize contrast without slowing scan times, and it can quicken scan times without losing image quality.

On the research front, the company will announce the final results of its multicenter brain attack trials. In this regard, Picker will show FDA-cleared imaging protocols for diffusion imaging and dynamic tissue intensity analysis (perfusion imaging). The diffusion package is specifically approved as an enhanced method for examining acute stroke. The software automatically creates directional diffusion images, apparent diffusion coefficient (ADC) images, and ADC trace maps. The tissue intensity provides relative cerebral blood volume measures and mean transit time maps.

The company will describe advances in cardiac MRI, including results produced by Picker's new cardiac RF surface coil. Visitors can see the latest Picker development efforts related to peripheral vascular MRA. High-field spectroscopy results will be shown.

Picker is also investing resources in mid-field MRI. It will present a clinical proof statement for the Apollo, a 0.5-tesla short-bore scanner introduced last year. A 500-MHz host computer and cardiac RF coil will be introduced as options for the Apollo this year.

Shimadzu. Magnex Epios will be the focal point of Shimadzu's MRI exhibit. Offered in 1- and 1.5-tesla versions, Epios injects the power of 20-mtesla/m gradient coils and a new surface coil series to improve image acquisition. Its new workstation is 10 times faster than older models to complete slice reconstructions as fast as 0.2 sec.

Siemens. Siemens will emphasize innovative solutions for improved productivity with the 1-tesla Harmony and 1.5-tesla Harmony, its year-old, short-bore super-cons, and the 0.2-tesla Magnetom Open Viva, its permanent magnet, open-style scanner.

To be shown as a work-in-progress, real-time interactive scanning promises to increase the operator's control over scanning parameters during image acquisition. Unlike MR fluoro techniques that perform in near real-time, the operator can scan the anatomical region of interest while simultaneously changing the scan plane and image contrast parameters. Offered as an option to Harmony and Symphony, real-time interactive scanning has implications for improved blood flow assessments, interventional MR, and trauma applications.

Siemens' productivity theme also applies to Care Bolus, a new, real-time contrast bolus tracking technique for Harmony and Symphony. While operating in a real-time 2-D mode, Care Bolus allows the radiologist to observe injected contrast approach the area of interest.

Visitors to the Siemens booth will notice evidence of Siemens' commitment with DICOM compliance throughout its MR product line. It includes compliance with DICOM worklist standards to facilitate RIS/HIS system integration. The next software releases for Symphony, Harmony, Magnetom Impact Expert, Vision, and Open Viva will also feature software to comply with DICOM query and retrieve standards.

Progress on Siemens' Sonata cardiovascular MRI program will be documented, along with presentations on its experimental 3-tesla Allegra head scanner and modifications to a model of the Open Viva designed for interventional applications in the operating room.

Toshiba. Toshiba will emphasize the sales record of the Opart, a cryogenless, superconducting, 0.35-tesla open-style scanner that was introduced at the 1996 RSNA conference. The company expects to have delivered 150 Oparts to customers around the world by Thanksgiving. The capability of Toshiba's magnet manufacturing plant in San Diego was doubled this year to keep up with demand, and its assembly line in South San Francisco is operating at full capacity, according to company executives.

A new quad head coil, designed to reduce claustrophobia, will be introduced for Opart. A very large body coil (VLBC), shown as a work-in-progress, encompasses an 83-inch circumference for patients who weigh more than 500 pounds.

Toshiba officials will be prepared to talk about interventional applications for Opart. The discussion will emphasize the value of the magnetic field uniformity possible because of Opart's four-post design.

Toshiba will present Alotaview, a multimodality workstation that performs virtual endoscopy after reformatting 3-D CT and MR data sets. A remote console that complements Opart's Silicon Graphics user interface will be introduced, along with a new, short-bore superconducting magnet supplied by Oxford Magnet Technology for Toshiba's 1.5-tesla Visart.