A novel in-vivo optical projection tomography system and its application

Optical projection tomography (OPT) is a low-cost and high-resolution imaging technology which can provide three-dimensional (3D) images for samples from 1 to 10 mm. OPT has been greatly applied to drug efficacy evaluation or gene expression through imaging low scattering ex-vivo biological tissues, such as small animal extremities, animal embryos, etc. However, ex-vivo imaging cannot record dynamic change in biological tissues. Therefore, in-vivo application of OPT is promising. Our group has developed a novel OPT system for in-vivo imaging of small insects. The system consists of a continuous wave (CW) laser, three translation stages, a rotation stage, and a low-temperature electron multiplying (EM) CCD camera. The spatial resolution of our system is less than 10 μm with an imaging field between 1mm and 10mm. An imaging experiment costs less than 2 min containing a 5 s 3D reconstruction. Besides the system introduction, this paper also demonstrates the system operation processes and preliminary biological applications. Experimental results show that 3D in-vivo imaging of drosophila melanogaster pupae and other insects are easy to implement by using our system.