Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group

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

Not Accessible

Your library or personal account may give you access

Abstract

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 γ, which depends on the first and the second moments of the phase function, is known. If γ 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 γ, 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 γ 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 mm3 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 γ.

© 1999 Optical Society of America

Full Article  |  PDF Article
More Like This
Frequency-domain photon migration measurements of normal and malignant tissue optical properties in a human subject

Joshua B. Fishkin, Olivier Coquoz, Eric R. Anderson, Matthew Brenner, and Bruce J. Tromberg
Appl. Opt. 36(1) 10-20 (1997)

Monte Carlo study of diffuse reflectance at source–detector separations close to one transport mean free path

Frédéric Bevilacqua and Christian Depeursinge
J. Opt. Soc. Am. A 16(12) 2935-2945 (1999)

Spatially resolved absolute diffuse reflectance measurements for noninvasive determination of the optical scattering and absorption coefficients of biological tissue

Alwin Kienle, Lothar Lilge, Michael S. Patterson, Raimund Hibst, Rudolf Steiner, and Brian C. Wilson
Appl. Opt. 35(13) 2304-2314 (1996)

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Figures (12)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Tables (2)

You do not have subscription access to this journal. Article tables are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Equations (5)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Select as filters


Select Topics Cancel
© Copyright 2024 | Optica Publishing Group. All Rights Reserved