  Optical Projection Tomography (OPT) is a powerful tool for 3D imaging of
mesoscopic samples, thus of great importance to image whole organs for the
study of various disease models in life sciences. OPT is able to achieve
resolution at a few tens of microns over a large sample volume of several cubic
centimeters. However, the reconstructed OPT images often suffer from artifacts
caused by different kinds of physical miscalibration. This work focuses on the
refractive index (RI) mismatch between the rotating object and the surrounding
medium. We derive a 3D cone beam forward model to approximate the effect of RI
mismatch and implement a fast and efficient reconstruction method to correct
the induced seagull-shaped artifacts on experimental images of fluorescent
beads.
