Spatially resolved reflectance is a frequently used technique to derive optical properties and physiological parameters of tissue. We have evaluated the accuracy of this method by investigations on a set of phantoms with known optical properties derived from time-resolved measurements. The recorded profiles of spatially resolved reflectance were analyzed by a Monte Carlo model of photon transport. When we took only the shape of the measured profiles into account, we got only poor estimates of the optical properties. In particular, the absorption was strongly underestimated. The main reason for failing of this approach is that the shape of the measured profiles can be well described by many combinations of absorption and reduced scattering coefficients. The separation between scattering and absorption was strongly improved when the reflectance data were calibrated by using a reference phantom. We applied both the relative and the calibration based analysis method to reflectance data obtained from in vivo investigations on the kidney of rats. Despite the limited number of only 4 detector positions the calibration based analysis method yielded reliable estimates of the tissue optical properties.

Date Published: 14 March 2017
PDF: 9 pages
Proc. SPIE 10056, Design and Quality for Biomedical Technologies X, 100560W (14 March 2017); doi: 10.1117/12.2250552

Published in SPIE Proceedings Vol. 10056:
Design and Quality for Biomedical Technologies X
Ramesh Raghavachari; Rongguang Liang, Editor(s)