X-Ray Fan-Beam Luminescence Tomography

Nanophosphors emit near-infrared (NIR) light upon x-ray excitation, and can be functionalized as probes for in vivo molecular imaging. X-ray luminescence imaging maps a distribution of nanophosphors for diagnostic and therapeutic purposes. In this paper, we propose an x-ray fan-beam luminescence tomography approach to quantify a spatial distribution of molecular probes. A practical system is designed for x-ray fan-beam luminescence imaging in which an x-ray tube is collimated into a fan-beam of x-rays to excite nanophosphors on a cross-section through an object. The excited nanophosphors emit NIR light to be detected on the external surface of the object. The measured NIR light signal (2D) is used to reconstruct nanophosphors distribution on the cross-section (2D) of the object. In this imaging mode, the dimensionality of measurable data matches to that of the distribution of nanophosphors being excited, allowing an accurate and reliable image reconstruction. Numerical experiments are performed to demonstrate the feasibility and merits of the proposed approach.