Vendors refine offerings to boost efficiency

February 11, 2006

In the wake of the U.S. holiday of Thanksgiving every year, a city rises within the confines of Chicago's McCormick Place. It is a kind of radiological Epcot Center, a futuristic vision designed to dazzle; constructed of software, heavy iron, and handhelds; and swathed in platitudes.

In the wake of the U.S. holiday of Thanksgiving every year, a city rises within the confines of Chicago's McCormick Place. It is a kind of radiological Epcot Center, a futuristic vision designed to dazzle; constructed of software, heavy iron, and handhelds; and swathed in platitudes.

Attendees at the RSNA meeting have come to expect a vast technical exhibition. But this year, vendors also delivered something unexpected. As radiologists increasingly adopt the mantra of "work smarter," vendors at the meeting demonstrated that they are getting the message.

There were two standouts at the show that captured this trend: a new gamma camera that offers the option of streaming images and a new dual-detector, dual-tube premium CT scanner.

An Israeli start-up, Spectrum Dynamics, suggested its new D-SPECT technology has the potential to change the practice of nuclear medicine. Its assertion is firmly rooted in a solid-state detector, which is tied to a tungsten collimator and wrapped in specialized algorithms that in combination promise to turn static nuclear exams of the heart into streaming video.

The tens of thousands of frames captured in a D-SPECT study will show the washing in and washing out of radioisotopes in real-time, according to company representatives. And the resulting quantitation will lead to absolute measurements of blood flow. The implications of this capability are extraordinary.

"Today imaging is actually comparing one part of the heart to the other," said Dalia Dickman, Ph.D., vice president of clinical and regulatory affairs and chief biologist for Spectrum Dynamics. "If the whole heart is hypoperfused, there is no way of seeing that, meaning heart disease is being vastly underdiagnosed. This will end once you have absolute measurements."

Nuclear cardiology stands to gain enormously, not only in accuracy but productivity, if Spectrum Dynamics can perform as advertised. High-resolution cardiac scans will drop from 15 minutes to three. This development would also open the door to SPECT/CT with 64-slice scanners.

Such hybrids are only remotely possible with current technology, as no one would saddle a $3 million machine with a slow-moving gamma camera. But the speed of the D-SPECT camera, and the ability to undock and move it out of the way, could keep the CT from being underutilized while providing SPECT data for fusion.

Siemens broke new ground with its Somatom Definition dual-source CT. The scanner steps away from seven years of slice wars, with a design that focuses on the result of the scan rather than the number of slices.

Mounting two detectors and their x-ray tubes at a 90 degrees angle generates a slice every 83 msec. That's half the time of a conventional 64-slice scanner and fast enough to freeze a beating heart without the use of beta blockers, according to the company.

Because enough data might be acquired in a beat or two rather than the five or more required by current scanners, patient x-ray exposure could drop by half, according to Bernd Ohnesorge, Siemens' vice president of CT.

"We can get incredible scan speed, because the Somatom Definition can utilize power reserves up to 160 kW, driven by two 80 kW tubes and generators," Ohnesorge said. "We can utilize these power reserves to always scan at top speed and get high image quality independent of the patient size and weight."

DIGITAL RADIOGRAPHY

Digital x-ray introductions at the RSNA meeting were marked by subtler, albeit substantial changes. Agfa showcased advances in the chemistry underlying the phosphor plates that power its new computed radiography offering, DX-S. The device features DirectriX needle-based detector technology and Scanhead line-to-line CR plate stimulation and detector technology.

A key development is the use of cesium bromide, fashioned into needles, that improves the sharpness of images and the eraseability of the plates. The string of laser diodes built into the Scanhead stimulates the phosphor along a matched line of CCDs to record the emitted light.

Digital radiography pioneer Swissray has long relied upon CCD technology for its digital devices. Now customers can choose between CCD or the company's newly introduced flat-panel detector built around a silicon thin-film transistor. Either can be built into the company's C-arm ddRFormula or ddRCombi Trauma systems. Swissray is the only vendor to offer a choice in detector technology, according to the company.

GE launched its Definium series, featuring portable and fixed-room DR units. The fixed-room Definium 8000 promises to support more exams per hour, provide immediate access to images within seconds, and instantly transmit to multiple locations. The company's newest portable digital x-ray system, Definium AMX 700, replaces GE's long-standing AMX system, offering an integrated digital solution for transport throughout the hospital. Both are built around GE's amorphous silicon flat-panel detector technology.

ULTRASOUND DEVICES

The key trends in ultrasound revolved around productivity enhancements. Developers of cart-based systems applied high-end functionality to midtier offerings, while the makers of portable ultrasound systems boosted product power to levels approaching those of full-featured machines.

Enhancements to Toshiba's Xario include real-time 3D at the touch of a button with simultaneous 2D rendering. The device also features wide-band color Doppler, panoramic view, and advanced contour tracking for cardiology applications.

Philips introduced its highly mobile HD3, built around a broadband digital beamformer that delivers high-definition images. Advanced features include tissue harmonic imaging, pulsed Doppler capability, color Doppler, and color power angiography.

Zonare Medical Systems enhanced its z.one system with transducers designed for neonatal, infant, and pediatric imaging; calculation software to support abdominal and venous imaging; and a program that automatically recognizes and adjusts for differences in body sound propagation.

MINING MR

MR designers have been trying to balance speed and patient comfort for nearly 20 years, and that challenge continues.

Hitachi rose to fame in the U.S. on the wave of popularity accompanying open MR, but this year the company expanded its portfolio with the short-bore high-field Echelon. The scanner combines a compact magnet and eight-channel architecture with high-performance gradients capable of 30-mT gradient strength and 150T/m/sec slew rate.

Hitachi's parallel imaging technique, RAPID, first deployed on the company's midfield scanners, has been adapted for use on Echelon's brain, body, vascular, and orthopedic coils.

Regardless of how open MR fares in the future, Hitachi stands to do well as it taps into high field. Toshiba accomplished that feat two years ago with the launch of its short-bore 1.5T Excelart Vantage.

At the most recent RSNA meeting, Toshiba highlighted MR angiograms obtained without contrast media, an accomplishment possible with algorithms that use blood as its own contrast agent. The approach may be especially attractive in slow-flow situations, which are difficult to image with contrast, according to Bob Giegerich, director of MR.

An example is MR angiography below the knee.

"By the time the contrast medium gets to the knee, the bolus is a yard long," he said. "It may or may not get beyond that point. Contrast-free MRA never fails."

GE has been running at high-field strength since the advent of MR. This year, the company fine-tuned its offerings with the release of two new premium MR devices, the Signa HDx 3.0T and 1.5T, and an economy version, the 1.5T Signa HDe.

The high-end systems incorporate 32-channel architecture to support advanced clinical applications. The value-end HDe, which comes in four- and eight-channel configurations, is intended for buyers who perform less challenging applications.

Philips' SmartExam automates the planning, scanning, and processing of MR scans. Doing so decreases overall exam time, while increasing consistency and reliability, according to the company. The system runs on all Philips MR machines.

The process starts with settings stored in Philips' ExamCards, which are specific for the individual types of exams. SmartExam builds on these settings, automatically detecting anatomic landmarks in a survey scan of the patient. It then plans the diagnostic scans related to the patient's actual position in the magnet. The operator defines the spatial resolution, and SmartExam does the rest, automatically maintaining resolution and image contrast regardless of variations in the field-of-view, according to the company.