Full-field fan-beam x-ray fluorescence computed tomography with a conventional x-ray tube and photon-counting detectors for fast nanoparticle bioimaging

X-ray fluorescence computed tomography (XFCT) was performed on a high-intensity synchrotron radiation source or a pencil beam with a long exposure time due to the low emission and detection efficiency of x-ray fluorescence photons. For the first time, the feasibility and experimental results of a full-field fan-beam XFCT with a photon-counting detector array are presented. This full-field fan-beam XFCT consists of a conventional low-intensity x-ray tube, an energy-sensitive photon-counting detector array, and a tungsten pinhole collimator. A phantom containing gadolinium solution (Kα, 42.74 keV) was scanned for 30 min using a polychromatic x-ray fan beam with a third-generation computed tomography (CT) geometry. After scattering and attenuation corrections, experimental results showed that XFCT had better accuracy and performance than spectral CT. Full-field XFCT is a promising modality for biomedical imaging of exogenous molecular probes containing nanoparticles of high atomic number.