Division of Neurological Surgery, Department of Neurological Surgery, Nihon University School of Medicine, Tokyo, Japan.
Adv Exp Med Biol. 2010;662:205-12. doi: 10.1007/978-1-4419-1241-1_29.
Measurement of multichannel continuous-wave near-infrared spectroscopy (CW-NIRS) is dependent on the modified Beer-Lambert law, which includes optical pathlength (PL) as an essential parameter. PLs are known to differ across different head regions and different individuals, but the distribution of PLs for the whole head has not been evaluated so far. Thus, using time-resolved near-infrared spectroscopy (TR-NIRS), we measured the optical characteristics including PL, scattering coefficients (mu'(s)), and absorption coefficients (mu(a)) at three wavelengths (760, 800, 830 nm). Then, we constructed maps of these parameters on the subjects' head surface. While the PLs in nearby channels are similar, they differ depending on the regions of the head. The PLs in the region above the Sylvian fissure tended to be shorter than those in the other regions at all of the wavelengths. The difference in the distribution of PLs may be attributed to differences in tissue absorption and scattering properties. The current study suggests the importance of considering PL differences in interpreting functional data obtained by CW-NIRS.
多通道连续波近红外光谱（CW-NIRS）的测量依赖于修正后的 Beer-Lambert 定律，其中包括光程（PL）作为一个重要参数。PL 在不同的头部区域和不同的个体之间是已知的，但到目前为止，还没有评估整个头部的 PL 分布。因此，我们使用时间分辨近红外光谱（TR-NIRS）测量了包括 PL、散射系数（μ'（s））和吸收系数（μ（a））在内的光学特性，在三个波长（760、800、830nm）处。然后，我们在受试者的头部表面构建了这些参数的图谱。虽然附近通道的 PL 相似，但它们因头部区域而异。在所有波长下，在 Sylivian 裂上方区域的 PL 往往比其他区域的短。PL 分布的差异可能归因于组织吸收和散射特性的差异。本研究表明，在解释 CW-NIRS 获得的功能数据时，考虑 PL 差异的重要性。
