Dual-energy subtraction efficiency of different X-ray detector design and imaging parameters

Abstract Dual-energy imaging (DEI) enhances the visibility of materials of interest by selectively suppressing the contrast of non-relevant structures through a linear combination of two images acquired at distinct x-ray energies. The performance of DEI depends on multiple factors, including acquisition parameters (e.g., low/high kV settings and dose allocation) and detector design (e.g., x-ray converter type and pixel pitch). In this study, we evaluated the dual-energy subtraction efficiency (DSE), which is defined as the contrast-to-noise ratio normalized by the imaging dose, for various detector designs and acquisition settings via Monte Carlo simulations. The simulation framework was validated using measurements obtained from two CsI-based flat-panel detectors with different backplane technologies. The simulation results indicate that the pixel pitch and energy separation between low- and high-kV settings affect the DSE more significantly than dose allocation. The concept of DSE, including the findings of this study, provides guidance for optimizing detector design and acquisition protocols in the development of high-performance DEI systems.