Quantifying spatial localization of optical mapping using Monte Carlo simulations
Quantifying spatial localization of optical mapping using Monte Carlo simulations
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DOI：
10.1109/10.951512
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发表时间：
2001-10-01
影响因子：
4.6
通讯作者：
Knisley, SB
中科院分区：
文献类型：
--
作者：
Ding, L;Splinter, R;Knisley, SB
用于研究心脏活动空间分布的光学标测技术可分为两类。1)广场激发法，用宽场激发光照射染有电压或钙敏感染料的心脏，用图像或光电二极管阵列采集荧光。2)激光扫描法，用扫描激光照明，用光电倍增管收集荧光。这两种方法的荧光信号的空间局部化是未知的，可能取决于在激发和发射波长的光吸收和散射。我们测量了用di-4-ANEPPS染色或Rh237和Oregon Green 488BAPTA-1共染色的兔心脏组织在具有代表性的激发和发射波长的吸收系数(Mu(A))、散射系数(Mu(S))和散射各向异性系数(G)。然后用蒙特卡罗模型模拟了激发光和荧光发射光在三维组织中的吸收和散射。对于这两种方法，确定了整个组织的局部发射对从组织表面收集的荧光的贡献。我们的结果表明，空间定位取决于组织中的光吸收和散射以及所使用的光学映射方法。比激光束或阵列元件的收集区域大的组织区域有助于光学记录。
Optical mapping techniques used to study spatial distributions of cardiac activity can be divided into two categories. 1) Broad-field excitation method, in which hearts stained with voltage or calcium sensitive dyes are illuminated with broad-field excitation light and fluorescence is collected by image or photodiode arrays. 2) Laser scanning method, in which illumination uses a scanning laser and fluorescence is collected with a photomultiplier tube. The spatial localization of the fluorescence signal for these two methods is unknown and may depend upon light absorption and scattering at both excitation and emission wavelengths. We measured the absorption coefficients (mu (a)), scattering coefficients (mu (s)), and scattering anisotropy coefficients (g) at representative excitation and emission wavelengths in rabbit heart tissue stained with di-4-ANEPPS or co-stained with both Rh237 and Oregon Green 488 BAPTA 1. Monte Carlo models were then used to simulate absorption and scattering of excitation light and fluorescence emission light for both broad-field and laser methods in three-dimensional tissue. Contributions of local emissions throughout the tissue to fluorescence collected from the tissue surface were determined for both methods. Our results show that spatial localization depends on the light absorption and scattering in tissue and on the optical mapping method that is used. A tissue region larger than the laser beam or collecting area of the array element contributes to the optical recordings.