散乱特性実測による後方散乱型吸収分布推定法の開発

摘要

We have developed a technique to estimate the absorption coefficient (μ_a) of turbid medium by the time-resolved measurement of backscattered light, and verified its feasibility in simulation and experiments. For accurate estimation of the absorption distribution in a diffuse scattering medium, accurate scattering property of the medium is essential. Here, we newly developed a technique to obtain the important parameters required for the absorption estimation by measuring the scattering property of the medium using backscattered light. The results using the proposed technique were compared with those using the former technique in which the scattering property of the medium was assumed to be known and homogeneous. Through these simulations, the feasibility and the effectiveness of the proposed technique were verified.%後方散乱光を用いた生体断層イメージングの実現をめざし，これまで再構成方法の簡便な吸収係数分布推定法を考案し，シミュレーションおよび実験によりその有効性を確認してきた．この方法では，吸収係数分布推定精度向上のためには対象の正確な散乱特性の情報が不可欠である．今回，生体断層イメージングの高精度化をめざし，実測波形を用いて，散乱特性が未知な媒質の散乱特性を推定し，吸収係数分布推定に必要なパラメータを取得する手法を考案した．まず，シミュレーションにより精度よく散乱特性および必要パラメータが推定できることを確認した．次に，提案手法と散乱特性を既知，均一とする従来手法との間で吸収係数分布推定精度の比較を行い，提案手法の有効性を確認した．