Time domain X-ray luminescence computed tomography: numerical simulations.

X-ray luminescence computed tomography (XLCT) has the potential to image the biodistribution of nanoparticles inside deep tissues. In XLCT, X-ray excitable nanophosphors emit optical photons for tomographic imaging. The lifetime of the nanophosphor signal, rather than its intensity, could be used to extract biological microenvironment information such as oxygenation in deep tumors. In this study, we propose the design, the forward model, and the reconstruction algorithm of a time domain XLCT for lifetime imaging with high spatial resolution. We have investigated the feasibility of the proposed design with numerical simulations. We found that the reconstructed lifetime images are robust to noise levels up to 5% and to unknown optical properties up to 4 times of absorption and scattering coefficients.