PDF(Pubmed)
Abstract：
Functional near-infrared spectroscopy (fNIRS) is a widely used imaging method for mapping brain activation based on cerebral hemodynamics. The accurate quantification of cortical activation using fNIRS data is highly dependent on the ability to correctly localize the positions of light sources and photodetectors on the scalp surface. Variations in head size and shape across participants greatly impact the precise locations of these optodes and consequently, the regions of the cortical surface being reached. Such variations can therefore influence the conclusions drawn in NIRS studies that attempt to explore specific cortical regions. In order to preserve the spatial identity of each NIRS channel, subject-specific differences in NIRS array registration must be considered. Using high-density diffuse optical tomography (HD-DOT), we have demonstrated the inter-subject variability of the same HD-DOT array applied to ten participants recorded in the resting state. We have also compared three-dimensional image reconstruction results obtained using subject-specific positioning information to those obtained using generic optode locations. To mitigate the error introduced by using generic information for all participants, photogrammetry was used to identify specific optode locations per-participant. The present work demonstrates the large variation between subjects in terms of which cortical parcels are sampled by equivalent channels in the HD-DOT array. In particular, motor cortex recordings suffered from the largest optode localization errors, with a median localization error of 27.4 mm between generic and subject-specific optodes, leading to large differences in parcel sensitivity. These results illustrate the importance of collecting subject-specific optode locations for all wearable NIRS experiments, in order to perform accurate group-level analysis using cortical parcellation.
摘要：
功能近红外光谱（fNIRS）是一种广泛使用的成像方法，用于根据脑血流动力学绘制脑激活图。使用fNIRS数据对皮质激活的准确量化高度依赖于正确定位头皮表面上的光源和光电探测器的位置的能力。参与者头部大小和形状的变化极大地影响了这些光头的精确位置，因此，到达皮质表面的区域。因此，这种变化会影响NIRS研究中试图探索特定皮质区域的结论。为了保持每个NIRS信道的空间同一性，必须考虑NIRS阵列注册中特定受试者的差异。使用高密度漫射光学层析成像（HD-DOT），我们已经证明了相同HD-DOT阵列应用于10名静息状态参与者的受试者间变异性.我们还将使用特定于对象的定位信息获得的三维图像重建结果与使用通用光电二极管定位获得的结果进行了比较。为了减轻使用所有参与者的通用信息引入的错误，摄影测量法用于确定每个参与者的特定光点位置。本工作证明了受试者之间的巨大差异，即通过HD-DOT阵列中的等效通道对哪些皮质包裹进行采样。特别是,运动皮层录音遭受最大的光电二极管定位错误，通用和特定于受试者的光点之间的中值定位误差为27.4mm，导致包裹敏感度存在很大差异。这些结果说明了在所有可穿戴NIRS实验中收集特定对象的光电二极管位置的重要性。以便使用皮质分裂进行准确的群体水平分析。
