Simulation of x-ray fluorescence ghost imaging by inverse Compton scattering source: A feasibility study

Abstract

X-ray fluorescence computed tomography (XFCT) has shown great potential in molecular biomedical imaging. However, conventional XFCT has some limitations, including sensitivity and a trade-off between spatial resolution and dose. X-ray fluorescence ghost imaging (XRF-GI) makes it possible to realize high-resolution imaging with low doses. However, the efficient implantation of XRF-GI requires a quasi-monochromatic x-ray source. The inverse Compton scattering (ICS) source could meet the requirement well. In this study, we developed a Monte Carlo simulation model of an XRF-GI system based on the Geant4 toolkit. The simulation model was composed of an ICS source, a series of Hadamard pattern-based masks as a modulating system, a single-pixel energy-resolving detector, and a phantom embedded with gold nanoparticles (GNPs) of different concentrations as the contrast agent. The image reconstructed by the total variation-regularized least squares (L2-TV) algorithm was evaluated by four criteria, including the mean square error, the contrast-to-noise ratio, the coefficient of determination (R2), and the limit of detection. Compared to XFCT, the reconstructed image of XRF-GI has better performance in all four criteria, and the dose of XRF-GI was halved without a decrease in resolution. It was validated that the beam properties of the ICS source fitted well with the implantation of XRF-GI for different conditions. In conclusion, the XRF-GI by an ICS source has great potential for biomedical imaging.