论文标题
与频率域近红外光谱的脑血流动力学的双斜率成像
Dual-slope imaging of cerebral hemodynamics with frequency-domain near-infrared spectroscopy
论文作者
论文摘要
意义：这项工作针对浅表血液动力学对光学信号的污染，这是人脑非侵入性光学测量的主要障碍之一。 目的：确定频域（DS）测量频率域（FD）近红外光谱（NIRS）的最佳源探测器距离，并表现出对较深的组织（脑）与浅表组织（头皮）的双斜率（DS）成像的优先灵敏度。 方法：基于两层和均匀散射培养基中基于扩散理论的理论研究（内部）。视觉刺激和全身血压振荡期间人脑的DS成像的体内演示。 结果：平均距离（DS所需的两个源检测器距离之间）是深度灵敏度的关键因素。具有FD NIR的人枕叶的体内成像，平均距离为31毫米：（1）从FD相对于强度与强度的视觉刺激以及DS相对于单距离（SD），对视觉刺激的血液动力学反应更大； （2）FD相和DS的血流动力学主要由血流驱动，而SD强度的血液动力学主要由血液驱动。 结论：使用FD NIRS进行DS成像可能会抑制浅表血液动力学的混杂贡献，而无需依赖于短源检测距离的数据。这种能力对人脑的非侵入性光学测量可能具有重要意义。
Significance: This work targets the contamination of optical signals by superficial hemodynamics, which is one of the chief hurdles in non-invasive optical measurements of the human brain. Aim: To identify optimal source-detector distances for Dual-Slope (DS) measurements in Frequency-Domain (FD) Near-InfraRed Spectroscopy (NIRS) and demonstrate preferential sensitivity of Dual-Slope (DS) imaging to deeper tissue (brain) versus superficial tissue (scalp). Approach: Theoretical studies (in-silico) based on diffusion theory in two-layered and in homogeneous scattering media. In-vivo demonstrations of DS imaging of the human brain during visual stimulation and during systemic blood pressure oscillations. Results: The mean distance (between the two source-detector distances needed for DS) is the key factor for depth sensitivity. In-vivo imaging of the human occipital lobe with FD NIRS and a mean distance of 31 mm indicated: (1) greater hemodynamic response to visual stimulation from FD phase versus intensity, and from DS versus Single-Distance (SD); (2) hemodynamics from FD phase and DS mainly driven by blood flow, and hemodynamics from SD intensity mainly driven by blood volume. Conclusions: DS imaging with FD NIRS may suppress confounding contributions from superficial hemodynamics without relying on data at short source-detector distances. This capability can have significant implications for non-invasive optical measurements of the human brain.
