X-ray fan-beam luminescence tomography

Abstract

Nanophosphors emit near-infrared (NIR) light upon X-ray excitation, and can be functionalized as optical probes for in vivo molecular imaging. X-ray luminescence computed tomography (XLCT) combines the high sensitivity optical imaging with the high spatial resolution X-ray imaging to visualize specific molecular and cellular targets, pathways and therapeutic responses. In this paper, we propose an X-ray fan-beam luminescence tomography to quantify a spatial distribution of nanophosphors in a biological object. A practical imaging system is designed for the X-ray fan-beam luminescence imaging in which the X-ray tube is collimated into a fan-beam X-rays to excite nanophosphors on a cross-section of the object. The excited nanophosphors would emit NIR light to be detected on the external surface of the object. The measured NIR light signal (2D) is used to reconstruct a nanoparticle distribution (2D) on the cross-section. In this imaging mode, the dimensionality of measurable data matches to that of the nanophosphors image to be reconstructed, allowing an accurate and reliable image reconstruction. The numerical experiments are performed to demonstrate the feasibility and merits of the proposed approach.