Monte Carlo-based inverse model for calculating tissue optical properties. Part I: Theory and validation on synthetic phantoms.
A flexible and fast Monte Carlo-based model of diffuse reflectance has been developed for the extraction of the absorption and scattering properties of turbid media, such as human tissues. This method is valid for a wide range of optical properties and is easily adaptable to existing probe geometries, provided a single phantom calibration measurement is made. A condensed Monte Carlo method was used to speed up the forward simulations. This model was validated by use of two sets of liquid-tissue phantoms containing Nigrosin or hemoglobin as absorbers and polystyrene spheres as scatterers. The phantoms had a wide range of absorption (0-20 cm(-1)) and reduced scattering coefficients (7-33 cm(-1)). Mie theory and a spectrophotometer were used to determine the absorption and reduced scattering coefficients of the phantoms. The diffuse reflectance spectra of the phantoms were measured over a wavelength range of 350-850 nm. It was found that optical properties could be extracted from the experimentally measured diffuse reflectance spectra with an average error of 3% or less for phantoms containing hemoglobin and 12% or less for phantoms containing Nigrosin.
Palmer
Gregory M
GM
Department of Biomedical Engineering, 136 Hudson Hall, Box 90281, Duke University, Durham, North Carolina 27708-0281, USA.
Ramanujam
Nirmala
N
D000465:Algorithms; D000818:Animals; D003238:Connective Tissue / Q000737:chemistry* / Q000502:physiology*; D006801:Humans; D008954:Models, Biological; D015233:Models, Statistical; D009010:Monte Carlo Method; D019047:Phantoms, Imaging; D012031:Refractometry / Q000379:methods*; D013057:Spectrum Analysis / Q000379:methods*