Microspectroscopic measurement of the optical properties of rat liver in the visible region

Microspectroscopy is used to investigate optical properties of haemoglobin-free perfused rat liver. Visible spectra of 20 μm diameter spot size were measured in transmission and/or reflection modes as a function of the thickness (< 1200 μm) of the liver-edge. Optical density (OD) in transmission mode increased with the increasing liver thickness, whereas in reflection mode OD decreased but became almost constant above a certain thickness (c. 600 μm) of the liver. The Kubelka-Munk (KM) two-flux model, with a minor modification, was applied successfully to the analysis of the changes in OD as a function of the thickness. This approach estimates the KM absorption coefficient (E_KM), KM scattering coefficient (S_KM) and effective penetration depth (δ_eff) of the liver. The optical properties were similar to reported values, obtained with different methods.