Speaker
Description
Digital flat-panel detectors with indirect method typically uses amorphous silicon thin film transistor (TFT) or silicon CMOS (complementary metal oxide semiconductor) matrix arrays integrated with various scintillators for many X-ray imaging tasks. Conversion of X-ray energy into electric signals in flat-panel detector is implemented through a scintillating converter that emits visible lights under X-ray exposure. Because the visible light with green wavelength is emitted in scintillating film in all directions and it is changed into an electric signal in photodiode array, the light scattering and attenuation in scintillator grains play an important role for excellent spatial resolution in X-ray image quality.
In this work, high efficient scintillating films such as granular type Gd2O2S:Tb(GOS) materials with different 50-100um thickness were designed for ultra-high resolution(UHR) in digital X-ray imaging detectors. The used high resolution CMOS flat panel detectors in this experiment are consisted of silicon photodiode array with 50μm pixel pitch(theoretical resolution limit: 10lp/mm) and 20μm pixel pitch (theoretical resolution limit: 25lp/mm) respectively.
Their X-ray charaterization of high resolution CMOS imagers in combination with ultra-high resolution scintillation screens were investigated in terms of the relative light response to given X-ray exposure dose, modulation transfer function (MTF), noise power spectrum and X-ray imaging with various phantom. Through this expriment, the CMOS area imager with high resolution thin GOS films could implemented X-ray imaging task with ultra-high resolution. We predict that this new technology will show possibility for ultra-high spatial resolution in digital X-ray imaging tasks such as medical and industrial fields.
