This month's installment of the Technology & Industry Section highlights some of the ultrasound news from the 84th Scientific Assembly and Annual Meeting of the Radiological Society of North America (RSNA), held December 1998 in Chicago. Since last year, ultrasound has made significant advances in many areas, including three-dimensional imaging and digital encoding. Tissue harmonics and transducer technology also are discussed.
GE Medical Systems (Milwaukee) announced that it has extended
digitaltechnology into the ultrasound beam for its LOGIQ 700 MR
ultrasound system(figure 1). "This year's breakthrough is our most
exciting to date andrepresents a complete departure from
incremental changes in ultrasound to alevel of technology that will
advance the ultrasound industry to the nextlevel," said Omar
Ishrak, PhD, general manager of global ultrasound at GE.
"We've extended digital ultrasound technology beyond the
digitalbeamformer to a breakthrough new digital ultrasound beam
that simultaneouslymaximizes both resolution and penetration,
enabling operators of all skilllevels to image deeper and clearer
across virtually all patientpopulations," said Dr. Ishrak, adding
that this new technology can providephysicians and sonographers
with more information in less time.
According to GE, the digital beam improves signal-to-noise
ratios, enablinghigher-frequency operation. "In conventional
ultrasound, a singlefrequency or broad-band pulse must be selected
to balance resolution andpenetration. In other words, a choice has
to be made between excellentresolution and deep penetration, and
image quality is compromised in theprocess," explained Dr.
The new technology affects all probes, noted A. Thomas Stavros,
MD, directorof ultrasound at Swedish Medical Center (Denver). "I've
always believed inusing the highest frequency possible, and
digitally encoded ultrasound enablesyou to get deeper with higher
frequencies. It also has better spatial andcontrast resolution, so
you get a better-quality image and betterpenetration-without more
transmit power or more gain," said Dr. Stavros.
Siemens announces "real-time, real-world"3D ultrasound
The Ultrasound Group at Siemens Medical Systems, Inc. (Iselin,
NJ) released3-ScapeTM real-time 3D imaging, which allows
sonographers and clinicians toview 3D volumes building while they
scan the patient, for its SONOLINE®Elegra system. This technology
"promises to take 3D ultrasound imagingfrom its current role in
high-profile research environments to real-world,daily clinical
use," said Markus Kirchgeorg, MD, vice president ofworldwide
marketing for the Siemens Ultrasound Group. "We're at the dawnof
the age of real-world 3D ultrasound imaging. It's real-time, easy
to use,and relatively cost-effective to incorporate into daily
radiology andobstetrics/gynecology practices," said Dr.
With 3-Scape imaging, according to Siemens, physicians and
sonographers canview images in three scanning planes at once;
select any two-dimensional (2D)image slice from the 3D data set,
similar to the way slices are selected frommagnetic resonance (MR)
or x-ray computed tomography (CT) data sets; acquiregray-scale and
power Doppler information in a single scan; and rotate and 3Dvolume
up to 360 degrees. "Real-time interaction is extremely helpful
formonitoring high-risk pregnancies, where it is important to
evaluate the fetusin great detail," said Laurence Shields, MD, of
the Department ofObstetrics and Gynecology at the University of
Washington (Seattle)."During the course of an exam, the fetus
inevitably moves into positionsthat don't allow optimal imaging of
the fetal heart, face, or cord insertion.With 3-Scape imaging, we
can collect a 3D volume and have immediate access tothe view that
allows you to best evaluate the fetus," explained Dr.Shields.
According to Dirk Becker, MD, of the University of Erlangen
(Germany), 3Dimaging also is helpful for evaluating certain tumors.
"For patients withtumors of the pancreas, bile duct, or the
duodenal wall, 3D imaging appears tobetter demonstrate vessel
infiltration. It also offers a better way forevaluating tumors
treated through chemotherapy. Liver metastases, for example,can be
more accurately evaluated by charting 3D volumes instead of
2Dimages," he said.
Advances in extended imaging and 3D ultrasound
As a works-in-progress, Acuson Corporation (Mountain View, CA)
introducedthe PerspectiveTM advanced display option for its
Sequoia® and AspenTMsystems. The Perspective option provides
FreeStyleTM extended field-of-viewimaging, 3D fetal assessment
surface rendering, and 3D organ assessmentvolumetric rendering
(figure 2). The extended field-of-view feature providespanoramic
images, which may reduce or eliminate the need to assemble
multipleimages. According to Acuson, extended imaging may help
detect ligament ortissue damage in musculoskeletal exams and locate
disease and anatomicalreferences in vascular studies, in a
With 3D fetal assessment surface rendering, said the company,
sonographersand physicians can view the fetal face and limbs to
identify abnormalities inutero, such as cleft palate. The 3D organ
assessment volumetric rendering couldbe useful in defining prostate
boundaries as part of protocols for treatingprostate cancer using
external-beam radiation or implanted-seed radiotherapy.
Acuson recently signed an agreement with TomTec Imaging Systems,
GmbH(Munich, Germany), a pioneer in both 3D and dynamic 3D
ultrasound, toincorporate advanced TomTec 3D software technology
into the Acuson Sequoia andAspen systems. On the transducer front,
Acuson announced several new products,including the 4V1 designed
for patients who are difficult to image. With thistransducer and
NativeTM tissue harmonic imaging, "we were able to find aliver mass
in a 547-pound, technically difficult-to-image patient that
couldnot be imaged using any other method," said Robert Kuhnhein,
MD, chief ofultrasound at Scott and White Hospital (Texas).
3D for office and small clinics
Perception Ultrasound (Coral Gables, FL) announced the addition
of 3Dimaging to its GPS 5000 system. "This is the first time 3D
capabilitieswill be offered in a system intended for use in the
office and small clinicenvironment," said Martin E. Doyle,
president and chief executive officer(CEO) of Perception. According
to the company, this application is possiblebecause of the system's
computer-based design, which runs WindowsTM software inan open
architecture. "A cutting-edge feature such as 3D can be added
moreeasily than on traditional closed-architecture platforms,
resulting in a costsavings that can be passed on to customers,"
said Mr. Doyle.
Harmonics and flash echo imaging from Toshiba
Toshiba America Medical Systems (Tustin, CA) introduced a
harmonics packagefor the all-digital PowerVisionTM 6000 ultrasound
system, which enables it toperform advanced contrast imaging
studies, according to the company. Toshibarecently received
clearance from the Food and Drug Administration (FDA) tomarket its
harmonics package as well as its proprietary flash echo
application.Both features are available in the PowerVision 6000 and
With harmonics, an ultrasound system can adapt to the
characteristics ofvarious contrast agents, differentiating between
contrast and tissue echo. Bycapturing the higher frequencies
generated by contrast agent microbubbles, theultrasound study
provides more detailed information on how the contrast
Flash echo imaging was developed to enhance contrast images by
preservingmicrobubbles that enter the ultrasound field. With flash
echo, the harmonicultrasound pulses are transmitted intermittently,
at user-programmableintervals. This intermittent transmission
reduces microbubble destruction andallows new microbubbles to enter
the scan plane between pulse sequences.
Toshiba also introduced new broad bandwidth transducers for the
PowerVision6000, including a wide-aperture transducer for abdominal
imaging, two lineartransducers for deep-peripheral-vascular and
small-parts imaging, and aneonatal head transducer. "Transducer
technology allows for thecost-effective expansion of system use in
several areas," said RossHeaton, director of marketing in Toshiba's
Ultrasound Business Unit.
Hitachi provides "true system transducercompatibility"
The Ultrasound Division of Hitachi Medical Systems (Tarrytown,
NY)introduced a new line of transducers, Image MAX, compatible with
all thecompany's ultrasound systems, including the EUB-8000, 525,
420, and 405 models.Using proprietary multilayer crystal
technology, Hitachi added a trifrequencydesign to these
transducers. According to Hitachi, broadening the bandwidthshas
strengthened pulse response so clinicians can select the optimal
frequencymatched to individual patients. In addition, the company
said that highersensitivity achieved by using low impedance
circuitry further improves imagedetail with little degradation of
"The new technology makes premium imaging a reality at any price
point.Hitachi is the first ultrasound company that has true
system-transducercompatibility from top to bottom," said Connie
McNabb, RDMS, clinicalsupport manager at Hitachi. The company said
it offers the widest choice oftransducers for all ultrasound
applications, including radiology,obstetrics/gynecology, urology,
and surgery (including endoscopy andlaparoscopy).
Hitachi also introduced a new sonolaparoscopic transducer, the
EUP-OL334."In recent years, there has been a tremendous growth in
laparoscopicprocedures performed by surgeons. One of the
limitations of laparoscopy is thesurgeon's inability to palpate the
organ and perform comprehensive evaluations.Laparoscopic ultrasound
imaging can overcome some of these challenges becausethe surgeon
will have access to real-time anatomic and blood-flowinformation,"
said Ms. McNabb. According to Hitachi, studies show
thatsonolaparoscopy compares favorably to intraoperative
cholangiography, canimprove the accuracy of staging pancreatic
tumors, and can identify up to 30%more lesions than laparoscopy
alone or than CT.
New system from Seattle/Seoul joint venture
ATL Ultrasound (Seattle) and Medison (Seoul, Korea) jointly
announced theintroduction of the HDI 1500 all-digital broadband
ultrasound system, a mobilesystem for applications in radiology,
cardiology, vascular imaging,obstetrics/gynecology, and the
emergency room. According to the companies, thenew system can store
4,000 online images that can be recalled for comparisonand serial
studies. Data can be exported to a floppy disk and transferred
topersonal computer systems in either JPEG or BMP formats.
Ultrasound adjunctive to mammography
Ultrasound is becoming increasingly important as an adjunct to
mammography,according to Thomas M. Kolb, MD, a New York City
radiologist. "Ourresearch shows that women with dense breasts will
benefit if an ultrasound examis done in addition to a mammogram,"
said Dr. Kolb. In a study of 18,005women, 7,202 (40%) were
determined to have dense breasts. Density was graded ona scale of 1
to 4 (1=least dense, fattiest tissue; 4=most dense,
glandulartissue). In the subset of women with dense breasts (graded
2, 3, or 4), 80biopsy-confirmed breast cancers were detected in 75
women. Mammography alonedetected 56 (70%) of the cancers, whereas
ultrasound in addition to mammographydetected 75 (94%).
"Mammography is the most important screening test for breast
cancer,"said Dr. Kolb. "But although it detected 98% of cancers in
women with veryfatty breasts, it detected only 55% of cancers in
women with very densebreasts. Ultrasound in combination with
mammography can bring that overallnumber up to 93%," he added.