Applied Radiology

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. Ishrak.

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. Kirchgeorg.

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 contiguous image.

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 PowerVision 7000systems.

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 agentperfuses tissue.

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 signal-to-noise ratios.

"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.