French flat panel supplier ramps up to meet anticipated demand

Detector for digital mammography delayed

Trixell is ramping up production of its Pixium 4800, a dedicated digital detector for cardiac catheterization. Philips Medical Systems is already building the detector into its Integris Allura 9 (SCAN 3/20/02), obtaining up to a dozen flat panel detectors each month from the French components manufacturer.

Siemens Medical Solutions may soon join Philips with a version of its own cardiac cath product based on the Pixium 4800, according to executives at Thales Electron Devices, a major Trixell stakeholder along with Philips and Siemens. Shipments of the Pixium 4800 have begun flowing to the German manufacturer, according to Paul Maisonnier, Thales director of business development.

Philips and Siemens are relative latecomers to the digital market for cardiac cath products. GE Medical Systems beat them by two years, launching the Innova 2000 in February 2000 (SCAN 3/15/00).

Cardiac catheterization was an obvious first target for Trixell, because the market for these products can absorb the high cost of producing flat detectors capable of dynamic imaging, according to Maisonnier. But Thales and its joint venture Trixell will not stop there. Trixell is already developing detectors that might be used for other forms of dynamic-x-ray-based imaging, including angiography and general purpose radiography/fluoroscopy.

This does not mean that the end is anywhere in sight for conventional image intensifier (II) products, however.

"The II is going to live a very long time, because it has excellent performance and the cost is way below that of a dynamic plate," Maisonnier said.

Current advantages of flat panels--smaller size, lower weight, and less vulnerability to distortion--will not be enough to convince any but the most demanding customers to spend the extra cash for their purchase, he said.

Eventually prices will come down for detectors that can replace conventional IIs, but what such detectors from Trixell will look like has not yet been decided. Trixell would prefer to fabricate single plates comparable in size to IIs used in angiography and general R/F, but the company may have to stitch several smaller plates together. Small plates are easier to fabricate than large ones and the chance of unacceptable defects is less.

"Given the advantages, we are investigating (stitching) to implement such a product as soon as possible," Maisonnier said.

To achieve the current stage of development, Trixell has overcome noise and cooling problems in its flat detector, which, like GE's detector, incorporates an amorphous silicon plate with a cesium iodide scintillator. These problems were less of a concern in the development of the Pixium 4600, the large amorphous silicon detectors developed for radiography, because the plate generates static images.

But other problems stymied Trixell engineers when it came to creating a digital detector for mammography. Plans to develop such a detector were scrapped about two years ago, according to Maisonnier, when engineers concluded that pixel sizes could not be reduced from the current 100 microns to the 50 microns they believe is necessary for mammography.

Trixell is considering the use of materials other than amorphous silicon as the means for developing a digital mammography detector. Among these are amorphous selenium and lead oxide.