A method for determination of the absorption and scattering properties interstitially in turbid media
A method for determination of the absorption and scattering properties interstitially in turbid media
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DOI：
10.1088/0031-9155/50/10/008
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发表时间：
2005-05-21
影响因子：
3.5
通讯作者：
Zhu, TC
中科院分区：
文献类型：
--
作者：
Dimofte, A;Finlay, JC;Zhu, TC
我们已经开发了一种方法来快速确定组织的光学特性（吸收系数μ（α）和传输散射系数μ（ε ′）），通过测量光通量率源功率沿着一个线性通道在一个固定的距离（5毫米），从一个各向同性的点源的比率。漫射光由各向同性检测器收集，其位置由计算机控制的步进电机确定，定位精度优于0.1 mm。系统自动记录并绘制每单位源功率的光通量率作为位置的函数。将结果与扩散方程拟合以确定它，并且mu（s）′。我们使用一个积分球来校准每个源探测器对，从而减少个别校准的不确定性。为了测试该算法准确恢复组织的光学性质的能力，我们在由浓度为0.23、0.53和1.14%（μ（s）′ = 1.7- 9.1cm（-1））的Liposyn组成的组织模拟体模中，在浓度为0.002、0.53和1.14%（μ（s）′ = 1.7- 9.1cm（-1））的Higgins黑印度墨水的存在下进行测量。0.012和0.023%（μ（a）= 0.1- 1cm（-1））。为了进行比较，使用宽光束照明独立地确定每个体模的光学特性。我们发现用这种方法可以确定μ（a）和μ（s）'，其标准偏差分别为8%（15%）和18%（32%）。和mu（s）'。当前的方法S对于光学性质满足扩散近似要求的样品是有效的。由导管引入的空气腔引起的误差很小，除非mu（a）很大（mu（a）> 1 cm（-1））。我们提出了在人体前列腺使用这种方法测量的体内数据。
We have developed a method to quickly determine tissue optical properties (absorption coefficient mu(a) and transport scattering coefficient mu(s)') by measuring the ratio of light fluence rate to source power along a linear channel at a fixed distance (5 mm) from an isotropic point source. Diffuse light is collected by an isotropic detector whose position is determined by a computer-controlled step motor, with a positioning accuracy of better than 0.1 mm. The system automatically records and plots the light fluence rate per unit source power as a function of position. The result is fitted with a diffusion equation to determine it, and mu(s)'. We use an integrating sphere to calibrate each source-detector pair, thus reducing uncertainty of individual calibrations. To test the ability of this algorithm to accurately recover the optical properties of the tissue, we made measurements in tissue simulating phantoms consisting of Liposyn at concentrations of 0.23, 0.53 and 1.14% (mu(s)' = 1.7-9.1 cm(-1)) in the presence of Higgins black India ink at concentrations of 0.002, 0.012 and 0.023% (mu(a) = 0.1-1 cm(-1)). For comparison, the optical properties of each phantom are determined independently using broad-beam illumination. We find that mu(a) and mu(s)' can be determined by this method with a standard (maximum) deviation of 8% (15%) and 18% (32%) for A. and mu(s)' respectively. The current method S is effective for samples whose optical properties satisfy the requirement of the diffusion approximation. The error caused by the air cavity introduced by the catheter is small, except when mu(a) is large (mu(a) > 1 cm(-1)). We presented in vivo data measured in human prostate using this method.