Design and performance evaluation of different high-resolution scintillators in digital X-ray imaging detector

Abstract

In recent years, digital X-ray imaging detectors with indirect detection technology have been widely used in dental digital radiography such as intra-oral, panorama and dental CT. These indirect X-ray imaging detectors are based on the combination of a complementary metal-oxide semiconductor (CMOS) array with various high-resolution scintillating screens such as CsI, GOS materials. Currently, a CMOS panel-based indirect X-ray imaging detector with low radiation dose and excellent spatial resolution has been widely utilized for digital intra-oral radiography. In this work, different high-resolution scintillation screens such as FOS (fiber optic scintillator) with needle structured CsI:Tl and Gd2O2S:Tb(GOS) materials with different mass density(or screen thickness) were used to investigate and optimize the imaging characterization. The used different FOS screens are a highly X-ray absorption material that minimizes and removes the direct X-ray induced noise. The used scintillator's configuration parameters were tested and optimized for superior image quality at low X-ray exposure condition. For image characterization and optimization of the X-ray image device, different scintillating screens were directly combined on the bare high-resolution CMOS photodiode array. The imaging performance such as the relative light response to same X-ray exposure dose, modulation transfer function (MTF) and X-ray imaging with a tooth phantom was measured under practical dental condition with 60-65 kVp tube voltage and 10 mA tube current. The X-ray imaging with high spatial resolution could be implemented through the experimental results with a CMOS imaging detector using different FOS with CsI and GOS materials.