Time-resolved and spatially resolved measurements of the diffuse reflectance from biological tissue are two well-established techniques for extracting the reduced scattering and absorption coefficients. We have performed a comparison study of the performance of a spatially resolved and a time-resolved instrument at wavelengths 660 and 785 nm and also of an integrating-sphere setup at 550–800 nm. The first system records the diffuse reflectance from a diode laser by means of a fiber bundle probe in contact with the sample. The time-resolved system utilizes picosecond laser pulses and a single-photon-counting detection scheme. We extracted the optical properties by calibration using known standards for the spatially resolved system, by fitting to the diffusion equation for the time-resolved system, and by using an inverse Monte Carlo model for the integrating sphere. The measurements were performed on a set of solid epoxy tissue phantoms. The results showed less than 10% difference in the evaluation of the reduced scattering coefficient among the systems for the phantoms in the range 9–20 cm−1, and absolute differences of less than 0.05 cm−1 for the absorption coefficient in the interval 0.05–0.30 cm−1.
© 2003 Optical Society of America
(120.3150) Instrumentation, measurement, and metrology : Integrating spheres
(120.5820) Instrumentation, measurement, and metrology : Scattering measurements
(170.1470) Medical optics and biotechnology : Blood or tissue constituent monitoring
(170.3890) Medical optics and biotechnology : Medical optics instrumentation
Johannes Swartling, Jan S. Dam, and Stefan Andersson-Engels, "Comparison of Spatially and Temporally Resolved Diffuse-Reflectance Measurement Systems for Determination of Biomedical Optical Properties," Appl. Opt. 42, 4612-4620 (2003)