CT manufacturers roll out last year’s works-in-progress

CT vendors were exceptional in their predictability, as each bore product pathways to the RSNA meeting as true as rifle shots. High-end and midtier scanners appeared on cue, their makers registering claims for their own products and criticism of the competition. It all came as little surprise to anyone familiar with the RSNA exhibit floor.

The clinical potential for superpremium CT scanning and the means for achieving it had been enunciated in detail at the 2003 RSNA meeting. Vendors, hoping to get the jump on one another, lined up last year to announce their works-in-progress. The difference this year, they said, is that their scanners now are real - sort of.

GE Healthcare made enormous strides with its 64-slice LightSpeed VCT.

"Last year, the VCT was a gleam in our eye. It was simply a poster saying 'We got you covered,'" said Brian J. Duchinsky, global general manager of GE Healthcare's CT Imaging Business. "Now it is doing the heart in four beats."

But the company still has only one clinical site. Ditto for Philips, which has a single luminary site operating its 64-slice.

Midtier systems were niched into applications outside radiology, part of a process that had begun months before. Multislice scanners were all the rage, as Siemens, Philips, and Toshiba unveiled new products dedicated to oncology.

Each vendor has or is developing a wide-bore gantry for radiotherapy simulations. Toshiba's work-in-progress Aquilion LB (Large Bore), a 16-slice scanner with a 90-cm gap, will be available in October.

"One of the great challenges in going to a much larger bore is the g force exerted on external components," said Doug Ryan, director of Toshiba's CT business unit. "This can cause more vibration."

Toshiba solved the problem by removing the tilt mechanism otherwise commonly built into the gantries.

This rush to oncology, however, was not new. GE Healthcare beat its competitors to the punch by a year when the company showed its CT simulator, the quadslice LightSpeed RT (radiation therapy) at the 2003 RSNA meeting.

Of the "new" CT scanners, Hitachi's CXR 4 may be the most noteworthy, not so much for its technology as for what it represents. The new product offered no significant advantages over its quadslice competition, nor would it be priced lower. But its appearance at the RSNA signified a turning point for Hitachi, whose equipment had not graced the McCormick Center since it appeared under the Philips label in the 1990s. And the scanner was available to begin shipping.

Hitachi's move back into CT might have been anticipated. Five months earlier, at the Society of Nuclear Medicine meeting, the company displayed a hybrid scanner composed of a CTI-supplied PET and a homegrown quadslice CT. Now Hitachi is going to market the CXR 4 to the entrepreneurs who made the company a success in open MR.

About 1400 sites in the U.S. operate Hitachi open MR scanners, according to Sheldon Shaffer, vice president and general manager of Hitachi MR. The company has already begun contacting them about the CXR 4.

"We have been getting a very favorable response," he said.

The scanner will be priced about the same as other quadslice scanners: under $500,000. The CXR 16 will also be competitively priced when introduced, which could happen this summer, Schaffer said. Attracting buyers to the CXR line will be Hitachi support and the proven quality of its medical imaging products.

Just as predictable as the products and the claims was the criticism of Siemens' two 64-slice scanners, the Sensation 64 and Sensation Cardiac. The two superpremium systems were denigrated as not being true 64-slice scanners but 32s propped up by a flying focal spot that provides two nearly simultaneous data points per detector row. Detractors had voiced the same opinions when the system was unveiled as a work-in-progress 12 months earlier.

There is a reason for the criticism. Making detectors with 64 rows is more difficult than making ones with 32. But, by achieving 64 slices with a 32-row detector, Siemens improved resolution and got a sales jump on competitors. When the RSNA show opened, the German company had installed 45 of its 64-slice scanners. By year's end, more than 100 had been installed.

Competitors trailed no matter what criteria were used. Toshiba had six Aquilion 64s installed at the start of the show. A seventh was scheduled for installation in early 2005. GE and Philips each had installed just one each by the start of 2005, although both said that number would grow quickly in the year ahead.

Even accepting the criticisms of the Sensation 64 and Cardiac - that they were really lesser slice systems - the numbers still favored Siemens. By year's end, Philips had managed 60 installations of its Brilliance 40, which entered full production in October. By the end of January, Toshiba expects to match Philips' number with 60 Aquilion 32s installed. By Jan. 1, GE had installed three LightSpeed Pro 32s.

Siemens' is trailing competitors, however, in releasing a lower cost alternative to its 64-slice generation. The company's Sensation 40, whose 20-row detector produces 40 slices per rotation by virtue of the same technology that gives the Sensation 64 and Sensation Cardiac their boost, will enter full production six months from now.

The company also plans to introduce by early 2006 a 16-slice scanner for its budget-oriented upgradable Emotion family, which currently has three members. It already offers a 16-slice model of the Sensation platform.

At the RSNA meeting, Siemens expanded its portfolio further with a dual-slice scanner. Spirit, slated for release in spring 2005, will be positioned as an entry level scanner for those who don't yet have CT, a cost-effective replacement for single-slice scanners, or an additional CT in overworked facilities. It generates 1-mm slices at rotational speeds of either 1 or 0.8 sec.

"We have expanded and revamped our multislice families to cover every business need," said Bernd Montag, Ph.D., president of Siemens CT.

For the time being, relatively few superpremium scanners have been installed, compared with the thousands of multislice CT scanners put in since the genre was launched in 1998. The numbers of 64-slice scanners are sure to rise for all vendors, however, just as the numbers of quad- and 16-slice scanners shot up in the months and years following their release.

This next generation, and its lower priced alternatives at 40 and 32 slices, will serve as new benchmarks of power and speed. But for how long is difficult to say. Sixteen-slice scanners were on the market less than four years after their quadslice predecessors. The 64-slice generation followed just two years after the 16s. Contrast this with the nine-year reign of single-slice spiral CTs and the nearly two decades that single-slice step CT scanners enjoyed.

The R&D cycle has to stop getting shorter if vendors are to reap much of a return on their investment. If it does, it won't happen because the technology can't continue to advance so quickly, but because clinicians need time to get accustomed to the new technology.

"The technology has gone so far so fast that we think there will be stabilization with 64-channel technology," said Jim Green, general manager of Philips CT business unit. "The applications will have to be validated for clinical efficacy in order to really make proper use of this technology."