In-vivo Imaging of Gadolinium Nanoparticles Using Benchtop XFCT System

X-ray fluorescence computed tomography (XFCT) is a quantitative imaging technique which detects the characteristic x-ray fluorescent (XRF) photons emitted from the target element in the object. XFCT experiments were first performed using synchrotron as the incident beam in order to obtain the XRF signal with high intensity and low scattering background. However, consider that the synchrotron will not be soon used for clinical application due to its limited access, researchers focus more on the benchtop XFCT system with conventional polychromatic source in recent years. Recent XFCT experiments aimed at small animals mainly use iodine (I), barium (Ba), gadolinium (Gd) or gold (Au) as the contrast agent. In this paper, we reported our latest in-vivo imaging study using our benchtop XFCT device with conventional cone-beam x-ray source and a linear-array photon counting detector. About 0.35 ml Gd nanoparticles (GdNPs) solution which consists of 2% NaGdF4 was injected into a nude mouse (weighted 20 g). 45 projections were obtained for image reconstruction with scanning time set at 10s per angle. The results show that the distribution of GdNPs in the mouse were well reconstructed. The benchtop XFCT device presented in this work has the capacity to obtain the bio-distribution of GdNPs, which may be helpful in relevant nanoparticle research.