Effects of x-ray excitation voltage on X-SWIR intensity and x-ray dose

Abstract

X-ray excited shortwave infrared (X-SWIR) imaging attracts much attention because of its advantages in optical deep imaging. However, the X-ray used for X-SWIR imaging brings risk of radiation to organism. How to better realize the synergistic optimization of X-ray dose and luminous efficiency with proper X-ray excitations is especially important for further application. To indicate the effects of X-ray excitation voltage on the X-SWIR light efficiency, the paper builds up an evaluating method, considering the variation of both X-SWIR intensity and X-ray dose along with the X-ray excitation voltages. Based on the method, the X-SWIR intensity and X-ray dose with different X-ray voltages are tested. By calculating the X-SWIR luminescence intensity with unit absorption dose at different X-ray voltages, the influence of X-ray energy on luminous efficiency is revealed. Results show that the dose efficiency of the probe is related to the X-ray energy, and it is the highest under 30-40 kV X-ray excitation (average energy of 10-20 keV). The conclusion is that the proposed evaluating method is feasible for assessing the luminescence efficiency and providing a reference for the practical application of X-ray luminescent nanoprobes. It helps understanding the X-ray luminescence theory, optimizing the X-ray excitation, reducing the X-ray dose while maintaining the X-SWIR luminescence intensity, which is meaningful for practical application of X-SWIR imaging in vivo.