New CCD sensors promise low-cost digital radiography

Two new digital radiography sensors developed by Kodak may bring low-cost, high-quality digital radiology to the field. The new charge-coupled devices record the flashes of light that occur when x-rays strike scintillators, turning flashes into electrical signals that are processed into radiographs.

Kodak's new sensors, developed by the company's Image Sensor Solutions group, serve as cornerstones for digital sensors that are less costly than amorphous silicon or amorphous selenium DR flat panels. And the technological advance represented by one of the new chips promises even greater savings.

The 9-million pixel KAF-09000 features a large pixel size of 12 microns and, consequently, about three times greater sensitivity than the current KAF-16801 CCD.

This increased sensitivity offers users the potential switch from a cesium iodide screen to less costly options such as a gadolinium oxide screen or a lens assembly for coupling the scintillator to the CCD chips.

The new 16-million pixel KAF-16803, with its 9-micron pixel size, offers higher resolution than the KAF-16801 and about a third less noise.

The smaller pixel size, which increases resolution, is less sensitive than the other new sensor. But it still offers about 20% better sensitivity than the current model.

Several commercial DR systems use Kodak's older model sensor. These products could be easily upgraded to the new generation of CCDs, as the new sensors share the same package and "pin-out" configuration as the current KAF-16801 device.

The new sensors have the added advantage of being protected against blooming artifact, seen under some conditions with CCD-based DR systems.

Evaluation units for the new chips are being made available to makers of end-user products so they can assess potential for the sensors' use in their own proprietary systems.