A Parallel Excitation Based Fluorescence Molecular Tomography System for Whole-Body Simultaneous Imaging of Small Animals

Abstract

Challenges remain in imaging complete dynamic physiological processes in vivo through the whole small animal body using fluorescence molecular tomography (FMT). In this article, a novel non-contact full-angle FMT system that enables whole-body simultaneous imaging of small animals is presented. The whole-body simultaneous imaging ability is achieved by employing a line-shaped parallel excitation source, which can provide extended spatial sampling dataset to reconstruct multiple fluorescent targets distributed in whole animal body during one full-angle FMT imaging process. The key performances of this system were evaluated by a series of experiments. Quantitation linearity for over two orders of magnitude of fluorescence markers concentration was demonstrated, and an accessible simultaneous imaging domain of 4.0 x 1.5 cm² could be achieved utilizing the parallel excitation pattern. Moreover, the in vivo imaging feasibility and performance were validated by localizing two fluorescent targets implanted at different positions of a nude mouse. The results suggest that compared with conventional single point excitation FMT system, the proposed system can achieve a whole-body simultaneous imaging domain and impart the ability to image complete dynamic physiological processes in vivo.