Multi-layer x-ray detector for diagnostic imaging

Abstract

X-rays from an x-ray tube ( ) pass through an examination region ( ) and are detected by a single or two-dimensional x-ray detector ( ). The x-ray detector ( ) includes an array ( ) of photodiodes, CCD devices, or other opto-electrical transducer elements. A matching array ( ) of transparent scintillator crystals, e.g., CdWO , is supported on and optically coupled to the photoelectric transducer array. A layer ( ) of a high efficiency scintillator with a good spectral match with the opto-electrical transducer array but with limited light transmissiveness is optically coupled to the transparent scintillator array. The layer ( ) is preferably zinc selenide ZnSe (Te). Electrical signals from the transducer array are reconstructed ( ) into an image representation and converted into a human-readable display ( ). To reduce cross-talk, the zinc selenide layer is etched with pits ( ), sliced into strips ( ′), cut into rectangles ( ″), or has channels ( ) cut into it. Scatter grids ( ) are advantageously received in the channels. Alternately, the zinc selenide can be powdered, encased in a transparent binder, and applied as a coating layer ( ″′) to the individual transparent scintillator elements.