Light Intensity Attenuation in the Rat Brain Tissue Assessed by Television Photometry

  • András Eke
  • Cornélia Ikrényi
  • Enikő Sárváry
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 345)


Methods for non-destructive spectrophotometric assessment of brain metabolism, oxygenation, blood flow and microcirculation in vivo has become increasingly important to researchers in the last three decades. The high spatial and temporal resolution offered by the optical approach, its non-destructive nature has also attracted considerable interest to the rapidly growing field of optical imaging of brain function and metabolisms1. The use of near infrared (NIR) light has opened the perspective for non-invasive monitoring of cerebral oxygenation2 and time-resolved NIR-spectroscopy by direct measurement of the optical pathlength of photons made absolute measurement possible3,4 and also proved to be an excellent tool to study photon migration in the brain tissue. Most of the surface fluororeflectometric methods work in the shorter wavelength range where it remains still difficult to analyze light penetration into the brain tissue since attenuation of light occurs over much shorter distances than that time-resolved spectroscopy can currently handle with adequate resolution4. A direct determination of the catchment volume of these measurements at the very site of photometric detection assumes a direct measurement of light attenuation profile in the tissue and becomes important when proper interpretation of in vivo data5,6,7,8,9 or calculation of absolute values from these data is needed. These questions have gained increasing importance during the methodological development of multiparametric imaging of microregional circulation in the brain cortex9,10. The primary objective of the present study, therefore, was to approach these problems experimentally by assessing light attenuation kinetics ex vivo in the brain within the visible wavelength range (589 nm) by measuring signal contribution from different depth of rat brain samples, among them, the cortical region of the brain where reflectometric measurement is usually.


Light Attenuation Cortical Gray Matter Photometric Detection Backscatter Intensity Short Wavelength Range 
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Copyright information

© Springer Science+Business Media New York 1994

Authors and Affiliations

  • András Eke
    • 1
    • 2
  • Cornélia Ikrényi
    • 1
    • 2
  • Enikő Sárváry
    • 1
    • 2
  1. 1.Experimental Neuropathology, Department of PathologyUniversity of Alabama at BirminghamBirminghamUSA
  2. 2.Experimental Research Department, 2nd Institute of PhysiologySemmelweis University of MedicineBudapestHungary

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