Repository logo

Infoscience

  • English
  • French
Log In
Logo EPFL, École polytechnique fédérale de Lausanne

Infoscience

  • English
  • French
Log In
  1. Home
  2. Academic and Research Output
  3. Journal articles
  4. In Vivo Local Determination of Tissue Optical Properties: Applications to Human Brain
 
research article

In Vivo Local Determination of Tissue Optical Properties: Applications to Human Brain

Bevilacqua, Frédéric
•
Piguet, Dominique
•
Marquet, Pierre
Show more
1999
Applied Optics

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.

  • Details
  • Metrics
Type
research article
DOI
10.1364/AO.38.004939
Web of Science ID

WOS:000081902000024

Author(s)
Bevilacqua, Frédéric
Piguet, Dominique
Marquet, Pierre
Gross, Jeffrey D.
Tromberg, Bruce J.
Depeursinge, Christian  
Date Issued

1999

Published in
Applied Optics
Volume

38

Issue

22

Start page

4939

End page

4950

Subjects

[MVD]

•

Medical optics and biotechnology : Light propagation in tissues

•

Medical optics and biotechnology : Photon migration

•

Medical optics and biotechnology : Spectroscopy, tissue diagnostics

•

Medical optics and biotechnology : Turbid media

•

Scattering : Multiple scattering

Editorial or Peer reviewed

REVIEWED

Written at

EPFL

EPFL units
LOA  
Available on Infoscience
August 2, 2009
Use this identifier to reference this record
https://infoscience.epfl.ch/handle/20.500.14299/41940
Logo EPFL, École polytechnique fédérale de Lausanne
  • Contact
  • infoscience@epfl.ch

  • Follow us on Facebook
  • Follow us on Instagram
  • Follow us on LinkedIn
  • Follow us on X
  • Follow us on Youtube
AccessibilityLegal noticePrivacy policyCookie settingsEnd User AgreementGet helpFeedback

Infoscience is a service managed and provided by the Library and IT Services of EPFL. © EPFL, tous droits réservés