Influence of a skull cranial window on the measurement of haemoglobin concentration in cortical tissue by multi-spectral imaging analysis

Koichiro Sakaguchi, Shunsuke Furukawa, Satoshi Matsuo, Naotaka Sakashita, Takushige Katsura, Kyoko Yamazaki, Hideo Kawaguchi, Atsushi Maki, Eiji Okada

Research output: Contribution to journalArticle

2 Citations (Scopus)


The simplified cranial window, which is transparent thinned skull, has been used for the optical imaging of cortical tissue of small animals to measure the concentration change in haemoglobin as an intrinsic signal of brain activation. The multi-spectral images of the cortical tissue of guinea pigs through the skull cranial window were compared with those of the exposed cortex to evaluate the influence of the scattering and absorption properties of the skull on the measurement of the concentration change in haemoglobin. Although skull thickness affects the sensitivity of the optical signal due to a decrease in mean optical path length in the cortical tissue, the influence of the skull cranial window on the wavelength dependence of optical path length can be ignored when the skull thickness is less than approximately 100 mm. Accurate concentration changes in oxygenated and deoxygenated haemoglobins can be calculated from the optical signal measured through a skull cranial window and the wavelength dependence of optical path length for the exposed cortex.

Original languageEnglish
Pages (from-to)74-80
Number of pages7
JournalOptical Review
Issue number2
Publication statusPublished - 2009 Mar 1



  • Biomedical optics
  • Brain activity
  • Cranial window
  • Multi-spectral imaging
  • Optical intrinsic signal
  • Optical path length
  • Thinned skull

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

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