Ultrasound Notes From RSNA 1999

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Ultrasound Notes From RSNA 1999

Written by Neil T. Specht, M.D..

As expected, RSNA 1999 proved to be a mammoth undertaking for any registrant who wanted to attend refresher courses, review the scientific exhibits, visit the technical exhibits and enjoy the magnificent cuisine of Chicago. This year, the major vendors of ultrasound equipment unveiled some significant advances for existing platforms: ATL presented SonoCT, real-time compound imaging which reduces image artifacts and improves contrast and detail resolution especially valuable in imaging small parts; Acuson presented software upgrades for their Sequoia and Aspen platforms; Seimens presented software upgrades for their 3-scape imaging technology as well as display of their new Sonoline Adara system. Toshiba, the worldwide leader in ultrasound sales, is putting forth a major effort to bring itself to the forefront of ultrasound imaging in the North American market with the development of their high-end system, PowerVision 8000. Time will tell whether they can capture market share and overcome existing brand loyalty.

By far, the most impressive advancement in ultrasound imaging equipment has been in the area of portable, miniaturized ultrasound systems. Two particular systems of note at this year's RSNA were the SonoSite 180 and Terason 2000 Handheld Ultrasound Systems. Three years ago, I was in the market for a portable ultrasound system with color Doppler capability primarily for abdominal and peripheral vascular ultrasound examinations for a mobile ultrasound service. The equipment options at that time were extremely limited and the portable unit purchased, after a short period of time, necessitated hiring a driver/deliverer of the ultrasound unit as most ultrasound technologists were unable to easily wield the somewhat bulky, 75-pound system between imaging sites. With the development of these two miniaturized systems, portable ultrasound capability has taken a quantum leap forward, giving ultrasound imaging service providers the ability to perform ultrasound examinations at virtually every bedside with ease. I envision these units to be extensively used in OB/GYN, Emergency Medicine, and Radiology departments and offices and in portable ultrasound services. With a price set at a fraction of larger high-end systems, multi-unit purchases will be common, providing these departments with immediate ultrasound capability at multiple sites.

Although SonoSite has major advantages with its high-end image quality and being first to market, the potential advantages of the Terason system with its PC interface are significant and this system deserves serious consideration once it is marketed by mid-year 2000. I hope to have these systems for evaluation in the near future and will provide a product review later in the year.

The SonoSite 180 system is a portable, hand carried (weighing just 5.4 pounds), self-contained, all-digital ultrasound system, producing digital quality images with a dynamic range of approximately 140 dB. SonoSite uses proprietary microchip technology developed by ATL Ultrasound, Inc. The miniaturization process uses ASIC (Application Specific Integrated Circuit) technology which integrates millions of transistors on a single chip, thereby reducing the equivalent circuitry of 10-20 circuit boards to a microchip 1 cm3 in size. There are three transducers currently available:

60 mm broadband (5-2 MHz) curved array for most abdominal and OB/Gyn applications
11 mm broadband (7-4 MHz) intracavitary array
15 mm broadband (4-2 MHz) array for transthoracic and abdominal applications.

Imaging modes supported include 2-D, zoom, narrow image sector and Color Power Doppler. PowerMap (TM) Directional Color Power Doppler mode was previewed at AHA and RSNA for cardiac and abdominal applications. (U.S. FDA 510(k) for PowerMap is expected in December 1999.) This system possesses an internal storage of 50 images for off-line printing and includes a peripheral connection for composite video output (NTSC/PAL) for VCR recording, video prints or for viewing on an external monitor. There is cineloop recording for frame-by frame review. This system operates on rechargeable lithium ion battery power or AC power. One drawback to this system is the unavailability of a linear array transducer which the company states will be available by mid-year 2000. Cost varies between $18,000 to $24,000 depending on system configuration. Additional information can be obtained from SonoSite.

terason

The Terason 2000 Handheld Ultrasound System takes miniaturization a step further with their "system in a probe" ASIC technology. Terason utilizes a new type of micro-electronics using Charge-Domain Processing (CDP) technology, developed at MIT, which allows creation of a relatively inexpensive chip that operates at tremendous speed with an extremely low power consumption. This imaging system integrates all the imaging circuitry within a 10 oz. scanhead and utilizes a FireWire connection for display on any PC platform including notebook, palmtop or desktop options. This plug-and-play system can thus make use of continuing advancements in PC and software technologies (e.g., processor speed, image display advancements, 3-D reconstruction, calculation packages, etc.) independent of the ultrasound imaging system. The power supply for the imaging system is derived from the connected PC. Transducers currently available are wideband curved, linear and phased-array varieties with frequencies from 2 to 10 MHz. An intracavitary probe is also available. Imaging modes currently supported are 2D, zoom, and image enhancement packages. Image storage is dependent on the PC being used but typical PC configurations will allow for storage of over 10,000 images. Cine storage and retrieval is also supported. Image/data transfer can be accomplished via DICOM network or internet. As of RSNA 1999, Color, Spectral, and Power Doppler were not incorporated in these systems, but will be available by mid-year 2000, according to Dr. Alice Chiang, President of Teratech Corporation. Tissue Harmonic Imaging is also planned as a future development. Cost of the system will depend on system configuration. Product shipments are scheduled for 2nd quarter 2000. Additional information can be obtained from Terason.