Continuous measurement of the heat-induced changes in the optical properties (at 1,064 nm) of rat liver.

The radiative transfer optical properties (absorption coefficient, scattering coefficient, and anisotropy of scattering) of slowly heated rat liver have been measured at 1,064 nm. Continuous measurements were made using double-integrating spheres and collimated illumination of the sample for up to 5,000 seconds heating with equilibrium temperatures of 48 degrees, 52 degrees, and 58 degrees C. Generally, the scattering increased, and the absorption and anistropy decreased at rates dependent on the heating temperatures. However, there was a large variability between samples.