Philips prepares to join upper echelon of CT vendors

By Greg Freiherr

With the unveiling of an advanced CT detector at the recent RSNA meeting, Philips served notice that it plans to enter the multislice marketplace next year.

Its first offering will be a quad-slice version of its flagship CT Secura. With the scheduled release of this system in the second half of 2001, the Dutch company will join the ranks of GE, Siemens, Marconi, and Toshiba as a top-flight vendor of CT equipment.

CT Secura was brought to market in 2000 as a single-slice scanner, but Philips has said repeatedly that the system was designed as a volumetric detector. All CT Secura systems now in the installed base will be upgradable to the new detector, called TrueView, according to the company.

The unveiling of TrueView was a milestone for Philips, which had been the only multimodality vendor not delivering multislice scanners. Reaching this landmark took several years of dedicated in-house efforts and the restructuring of a collaborative agreement with Hitachi, which had long provided the company with single-slice scanners.

"Three years ago we increased (our) investment in CT and redirected research activities with the goal of becoming the top player in CT," said Gerard Winkels, Philips' global marketing director for CT. "This is the first step toward showing our customers what they can expect when Philips takes control of innovation again."

For much of the last two decades, Philips had distributed scanners that were largely designed, engineered, and produced by Hitachi. Now, however, Philips substantially controls R&D and production of its own CT Secura product.

Philips provides the back-end technology, image handling components, interfaces for integration with the radiology department, and two workstations that include an operator interface. Philips also contributes the x-ray tube, based on MRC technology developed by the company; the volumetric detector, called TrueView; and a data reconstruction algorithm.

Hitachi designed and engineers the patient support as well as the gantry, which includes the rotating disk, slip ring, and data acquisition systems (DAS). The company assembles these front-end components with Philips' back-end hardware and software. Integration testing is done jointly by Philips and Hitachi. System validation is by Philips.

The heart of this new offering is the TrueView detector, which is composed of 16 detector arrays. Initially, only four slices will be generated by the scanner, one for each DAS attached to the detector. Eight application-specific integrated circuits (ASICs) will be built into the gantry of the scanner. These will handle the equivalent of two trillion instructions per second, using computing power approximately equal to that of 16,000 state-of-the-art PCs. The company expects to add DAS and ASICs to the detector until all 16 arrays built into TrueView are streaming data as individual channels. The first step‹eight channels‹will be taken in about 18 months. Sixteen channels could be available in three years, according to Winkels.

In the meantime, software capabilities will be integrated to make the diagnostic process as efficient as possible. A function called "Image on Demand" allows a limited number of relatively thick slices to be displayed. The radiologist can then home in on a region of interest. With Image on Demand, thinner slices can then be ordered from the volume to provide increased detail. Diagnosticians will also have the option of reconstructing the data into three dimensions.

Among the clinical benefits promised by these capabilities are improved nodule detection in the lungs, trauma evaluation, and enhanced CT angiography.

An added bonus of using the new technology will be reduced patient x-ray exposure, thanks to the exact sculpting of the x-ray beam to fit the multiple arrays built into the detector. Through this technology, called BeamRight, x-ray efficiency of close to 100% is achieved, according to the company.

Data quality is also improved, according to Philips. TrueView slices are free from the artifacts that can occur when multislice scanners generate data points for eight or more slices. TrueView minimizes artifacts by creating a data volume with spatial resolution virtually identical in all directions.

Ironically, even though TrueView is designed to acquire the data as a volume, images will be reconstructed as slices. One reason, said Winkels, is that radiologists are accustomed to evaluating data in this way. This could change, however, as more efficient methods of visualization are developed. n