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Optical properties of native and coagulated human brain structures

1997; SPIE; Volume: 2970; Linguagem: Inglês

10.1117/12.275082

1996-756X

Hans‐Joachim Schwarzmaier, Anna N. Yaroslavsky, Ilya V. Yaroslavsky, Thomas Goldbach, Thomas Kahn, Frank Ulrich, P. Christian Schulze, R. Schober,

Ocular and Laser Science Research

The laser-induced interstitial thermo-therapy of brain tumors requires an exact therapy planning. Therefore, the knowledge of the optical properties of native (na) and coagulated (co) tissue structures is important. In this study the optical properties of native and thermally coagulated (2 h, 80 degree Celsius) human white (n equals 14; na equals 7, co equals 7) and gray matter (n equals 14; na equals 7, co equals 7) were investigated (spectral range equals 360 - 1100 nm, spectral resolution 20 nm) in vitro using the integrating sphere technique combined with the inverse Monte-Carlo method. The (mu) a of the native gray matter decreased from 0.333 plus or minus 0.219/mm (360 nm) to 0.054 plus or minus 0.069/mm (1100 nm). The (mu) s varied between 14.13 plus or minus 4.26/mm (360 nm) and 5.53 plus or minus 1.80/mm (1100 nm). The g-value increased from 0.818 plus or minus 0.093 (360 nm) to 0.904 plus or minus 0.051 (1100 nm). Coagulation increased (mu) a and (mu) s by a factor up to 3 and g up to 16%. White matter exhibited a (mu) a between 0.253 plus or minus 0.055/mm (360 nm) and 0.100 plus or minus 0.052/mm (1100 nm) and a (mu) s between 40.20 plus or minus 9.18/mm (360 nm) and 28.65 plus or minus 6.83/mm (1100 nm). The g-value varied between 0.702 plus or minus 0.093 (360 nm) and 0.886 plus or minus 0.012 (1100 nm). Coagulation increased (mu) a up to a factor of three and the g-value up to 14% while the increase (approximately 1.25 fold) of (mu) s was not significant. We conclude the optical properties of human brain tissue change significantly due to thermal denaturation.