MRI firms bring slew of high-field introductions

December 15, 1999

Vendors bring innovation to higher field strengthsWhile much attention at the RSNA meeting was accorded to vendors presenting developments with higher field open scanners, several firms also took the opportunity to debut conventional high-field MR

Vendors bring innovation to higher field strengths

While much attention at the RSNA meeting was accorded to vendors presenting developments with higher field open scanners, several firms also took the opportunity to debut conventional high-field MR scanners.

Hitachi Medical Systems America introduced Celeris, a 1.5-tesla, whole-body MR scanner. The work-in-progress, short-bore Celeris includes high-performance 25 mtesla/m gradients with 150 mtesla/m/sec slew rate, which provides for such rapid imaging techniques as single-shot echo-planar imaging and MR angiography. A solid-state RF amplifier and a full complement of quadrature and phased-array coils are included.

Celeris is suited for diffusion-weighted imaging and perfusion imaging, as well as future applications such as high-speed cardiac imaging, according to the Twinsburg, OH-based firm. Hitachi’s Xp computer system provides faster processing of studies and offers improved clinical capabilities, according to the company. Celeris’ short-bore gantry offers a flared opening and interior illumination to enhance patient comfort.

Also debuting a 1.5-tesla scanner was Toshiba America Medical Systems, which unveiled Excelart. Excelart features a short-bore design with a 655-mm opening, which Toshiba claims is the widest in the industry.

Excelart also includes Toshiba’s work-in-progress Pianissimo technology, which reduces examination noise by as much as 90%, according to the Tustin, CA-based firm. Pianissimo employs a solid foundation for gradient support and special insulators to reduce the acoustic noise from the vibration of the gradient coil. Noise is further reduced through a unique gradient vacuum vessel and independent support direct from the ground, which shields against air vibration.

Excelart is suitable for MR angiography, as well as abdominal, liver, and spine imaging. It also features Toshiba’s SuperFase technology, a very short echo spacing half-Fourier RF refocused sequence, for imaging vascular structures in the abdomen and chest. With this technique, MRA images of venous and arterial vessels can be simultaneously visualized without the use of contrast agents, according to Toshiba.

Excelart also offers neurological imaging with single-shot echo-planar imaging for diffusion-weighted and perfusion-weighted imaging (work-in-progress) used in stroke detection.

Philips Medical Systems added to its MR product line with the debut of three additions to its Gyroscan family. Intera is a general-purpose system, while Intera CV is targeted for cardiovascular MR imaging. Intera I/T, a work-in-progress, is suited for interventional procedures and assistance in therapy, according to the Best, Netherlands-based vendor. Intera is available in 0.5-tesla, 1-tesla, and 1.5-tesla field strengths.

Philips also highlighted its work-in-progress Sensitivity Encoding (Sense) technique, which provides for immediate doubling of acquisition speed without major redesign of gradient systems, according to the company. With Sense, clinically practical four-fold or greater imaging speed increases may be possible, according to Philips.

Sense uses a parallel imaging approach, instead of ramped up gradient power, to speed image acquisition. It skips half or more of the gradient phase encoding steps typically needed to create a clinical image. The spatial information missed by skipping phase encoding steps is acquired by arrays of receiver coils with known sensitivities, according to Philips. A software-only enhancement, Sense is available for all Gyroscan systems.