Quantifying refractive index mismatch effects on cone beam optical CT scanner measurements

Abstract

A series of experiments are conducted to evaluate the effects of refractive index (RI) mismatch in readout with a Vista cone beam optical CT scanner. The changing optical attenuation in cuvettes of different colours and RI are quantified using a spectrophotometer, which shows decreasing attenuation as RI increases. A small jar of a colourless solution inside a large jar of another colourless solution with different combinations of fluids of varying RI is imaged in the Vista scanner. Large RI solutions surrounding small RI solutions create a converging lens, while small RI solutions surrounding large RI solutions create a diverging lens. The same dual-jar system is used with solutions of varying RI and colour (attenuation) to assess the effect of RI on attenuation coefficient determination.