Optical Review

, Volume 7, Issue 5, pp 426–431

Topographic Distribution of Photon Measurement Density Functions on the Brain Surface by Hybrid Radiosity-Diffusion Method

Authors

    • Department of Electronics and Electrical EngineeringKeio University
  • Yoshihiko Kashio
    • Department of Electronics and Electrical EngineeringKeio University
  • Martin Schweiger
    • Department of Computer ScienceUniversity College London
  • Hamid Dehghanim
    • Department of Medical Physics and BioengineeringUniversity College London
  • Simon R. Arridge
    • Department of Computer ScienceUniversity College London
  • Michael Firbank
    • University Department of RadiologyImaging Laboratory, Royal Victoria Infirmary
  • Eiji Okada
    • Department of Electronics and Electrical EngineeringKeio University
Regular Papers

DOI: 10.1007/s10043-000-0426-x

Cite this article as:
Ono, M., Kashio, Y., Schweiger, M. et al. OPT REV (2000) 7: 426. doi:10.1007/s10043-000-0426-x

Abstract

An accurate modelling of light propagation in the head is required to develop an algorithm to reconstruct the image of brain activity. Most previous studies have calculated the light propagation in two dimensional models because of their advantage in computation time and memory requirement over three dimensional models. However, in topographic imaging, the sensitivity distribution in the cross sections parallel to the brain surface which cannot be obtained from a two dimensional model is most important to reconstruct the image. In this study, the light propagation in three dimensional adult head models is calculated by finite element method and hybrid radiosity-diffusion method. The light propagation in the adult head is strongly affected by the non-scattering cerebrospinal fluid (CSF) layer surrounding the brain. The sensitive area is shifted toward the deeper region, and is spread around the CSF layer. The intensely sensitive region on the brain surface is broadly distributed between the source and detector. However, the sensitive region does not penetrate into the deeper part of the brain.

Key words

near infrared spectroscopydiffusion equationfinite element methodhybrid radiosity diffusion modeltopographic imagingphoton measurement density function
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Copyright information

© The Optical Society of Japan 2000