Spectroscopic diffuse optical tomography for the quantitative assessment of hemoglobin concentration and oxygen saturation in breast tissue

Near-infrared (NIR) spectroscopic diffuse tomography has been used to map t he hemoglobin concentration and the hemoglobin oxygen saturation quantitati vely in tissuelike phantoms and to determine average values in vivo. A seri es of phantom calibrations were performed to achieve quantitatively accurat e images of the absorption and the reduced scattering coefficients at multi ple optical wavelengths. A least-squares fit was applied to absorption-coef ficient images at multiple NIR wavelengths to obtain hemoglobin images of t he concentration and the hemoglobin oxygen saturation. Objects of varying h emoglobin concentration and oxygen saturation within highly scattering medi a were localized and imaged to within 15% of their actual values. The avera ge hemoglobin concentration and oxygen saturation of breast tissue was meas ured in vivo for two women volunteers. The potential application for the di agnosis of breast tumors is discussed. (C) 1999 Optical Society of America.