Quantifying the absorption and reduced scattering coefficients of tissuelike turbid media over a broad spectral range with noncontact Fourier-transform hyperspectral imaging

Absorption (mu (a)) and reduced scattering (mu (s)') spectra of turbid medi a were quanti fied with a noncontact imaging approach based on a Fourier-tr ansform interferometric imaging system (FTIIS). The FTIIS was used to colle ct hyperspectral images of the steady-state diffuse reflectance from turbid media. Spatially resolved reflectance data from Monte Carlo simulations we re fitted to the recorded hyperspectral images to quantify mu (a) and mu (s )' spectra in the 550-850-nm region. A simple and effective calibration app roach was introduced to account for the instrument response. With reflectan ce data that were close to and far from the source (0.5-6.5 mm), mu (a) and mu (')(s) of homogeneous, semi-infinite turbid phantoms with optical prope rty ranges comparable with those of tissues were determined with an accurac y of +/-7% and +/-3%, respectively. Prediction accuracy for mu (a) and mu ( s)' degraded to +/-12% and +/-4%, respectively, when only reflectance data close to the source (0.5-2.5 mm) were used. Results indicate that reflectan ce data close to and far hom the source are necessary for optimal quantific ation of mu (a) and mu (s)'. The spectral properties of mu (a) and mu (s)' values were used to determine the concentrations of absorbers and scatterer s, respectively. Absorber and scatterer concentrations of two-chromophore t urbid media were determined with an accuracy of +/-5% and +/-3%, respective ly. (C) 2000 Optical Society of America OCIS codes: 170.0110, 170.7050, 170 .6510, 070.2590, 120.3180.