In vivo local determination of tissue optical properties: applications to human brain.

Détails

ID Serval
serval:BIB_C545721E643E
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
In vivo local determination of tissue optical properties: applications to human brain.
Périodique
Applied Optics
Auteur(s)
Bevilacqua F., Piguet D., Marquet P., Gross J.D., Tromberg B.J., Depeursinge C.
ISSN
0003-6935 (Print)
ISSN-L
0003-6935
Statut éditorial
Publié
Date de publication
1999
Peer-reviewed
Oui
Volume
38
Numéro
22
Pages
4939-4950
Langue
anglais
Notes
Publication types: Journal ArticlePublication Status: ppublish
Résumé
Local and superficial near-infrared (NIR) optical-property characterization of turbid biological tissues can be achieved by measurement of spatially resolved diffuse reflectance at small source-detector separations (<1.4 mm). However, in these conditions the inverse problem, i.e., calculation of localized absorption and the reduced scattering coefficients, is necessarily sensitive to the scattering phase function. This effect can be minimized if a new parameter of the phase function gamma, which depends on the first and the second moments of the phase function, is known. If gamma is unknown, an estimation of this parameter can be obtained by the measurement, but the uncertainty of the absorption coefficient is increased. A spatially resolved reflectance probe employing multiple detector fibers (0.3-1.4 mm from the source) is described. Monte Carlo simulations are used to determine gamma, the reduced scattering and absorption coefficients from reflectance data. Probe performance is assessed by measurements on phantoms, the optical properties of which were measured by other techniques [frequency domain photon migration (FDPM) and spatially resolved transmittance]. Our results show that changes in the absorption coefficient, the reduced scattering coefficient, and gamma can be measured to within +/-0.005 mm(-1), +/-0.05 mm(-1), and +/-0.2, respectively. In vivo measurements performed intraoperatively on a human skull and brain are reported for four NIR wavelengths (674, 811, 849, 956 nm) when the spatially resolved probe and FDPM are used. The spatially resolved probe shows optimum measurement sensitivity in the measurement volume immediately beneath the probe (typically 1 mm(3) in tissues), whereas FDPM typically samples larger regions of tissues. Optical-property values for human skull, white matter, scar tissue, optic nerve, and tumors are reported that show distinct absorption and scattering differences between structures and a dependence on the phase-function parameter gamma.
Pubmed
Web of science
Création de la notice
05/04/2013 9:03
Dernière modification de la notice
20/08/2019 15:40
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