Multi-layer x-ray detector for diagnostic imaging

In a medical diagnostic imaging system which generates images from x-rays propagating from a radiation source to a radiation detector, the radiation detector comprising:

• a multi-layer scintillator including:
• an upper non-segmented scintillating layer of zinc selenide doped with tellurium, and
• a two-dimensional array of scintillators arranged to form a lower scintillating layer with higher z-ray absorption and shorter emission wavelength than tellurium doped zinc selenide and which is substantially transparent to the light emitted by the tellurium doped zinc selenide layer,the upper and sower layer being arranged serially along a path of x-ray propagation and presenting a substantially equal cross section to x-rays propagating along the path:
• and
• a two-dimensional array of opto-electric transducers, each transducer optically coupled to one of the scintillators of the lower scintillating layer, each of the opto-electric transducers combining the optical outputs from the upper scintillating layer and a corresponding one of the scintillators of the lower scintillating layer into an electrical output signal which is adapted for reconstruction into a diagnostic image.

A radiographic examination system comprising:

• an x-ray source for projecting x-rays through an examination region;
• an x-ray detector disposed across the examination region from the x-ray source, the x-ray detector including:
• a unitary doped zinc selenide scintillation layer which is etched in a two-dimensional first grid pattern to promote internal scattering of light within the zinc selenide layer, the zinc selenide scintillation layer converting x-rays into light,
• a two-dimensional array of light transmissive scintillators arranged in a second grid pattern and disposed below the zinc selenide scintillation layer to conduct the light from the zinc selenide scintillation layer and to convert x-rays that passed through the zinc selenide scintillator into light, and
• a two-dimensional array of opto-electrical transducers arranged in a third grid pattern, the first, second, and third grid patterns directly overlaying each other, such that the opto-electrical transducers convert light from the zinc selenide scintillator layer and the light transmissive scintillator array into electrical signals.

A radiographic examination system comprising:

• an x-ray source for projecting x-rays across an examination region;
• an x-ray detector disposed across the x-ray examination region from the x-ray source, the x-ray detector including:
• an array of opto-electrical elements,
• an array of light transmissive scintillators disposed on and optically coupled to the array of opto-electrical elements such that each of the opto-electrical elements converts light received from a corresponding transmissive scintillator into an electrical output signal, and
• a layer of higher efficiency scintillator material optically coupled to the transmissive scintillator array, a grid of pits being defined in a surface of the higher efficiency scintillator layer opposite the transmissive scintillator array to induce scatter, the higher efficiency scintillator layer being a scintillator material of limited opacity, higher x-ray conversion efficiency than the transmissive scintillators, and having a better optical match to a peak sensitivity spectrum of the opto-electrical transducers than the transmissive scintillators.

A radiographic examination system comprising:

• an x-ray source for projecting x-rays across an examination region;
• an x-ray detector disposed across the x-ray examination region from the x-ray source, the x-ray detector including:
• an array of opto-electrical elements,
• an array of light transmissive scintillators disposed on and optically coupled to the array of opto-electrical elements such that each of the opto-electrical elements converts light received from a corresponding transmissive scintillator into an electrical output signal, and
• a high efficiency scintillator layer divided into one of strips and rectangles which are dimensionally mismatched to the array of light transmissive scintillators and are optically coupled to the light transmissive scintillator array, the higher efficiency scintillator layer being a scintillator material of limited opacity, higher x-ray conversion efficiency than the transmissive scintillators, and having a better optical match to a peak sensitivity spectrum of the opto-electrical transducers than the transmissive scintillators.