Background

Arterial pulsation has been suggested as a key driver of paravascular cerebrospinal fluid flow, which is the foundation of glymphatic clearance. However, whether intracranial arterial pulsatility is associated with glymphatic markers in humans has not yet been studied.

Methods

Seventy-three community participants were enrolled in the study. 4D phase-contrast magnetic resonance imaging (MRI) was used to quantify the hemodynamic parameters including flow pulsatility index (PI_flow) and area pulsatility index (PI_area) from 13 major intracerebral arterial segments. Three presumed neuroimaging markers of the glymphatic system were measured: including dilation of perivascular space (PVS), diffusivity along the perivascular space (ALPS), and volume fraction of free water (FW) in white matter. We explored the relationships between PI_area, PI_flow, and the presumed glymphatic markers, controlling for related covariates.

Results

PI_flow in the internal carotid artery (ICA) C2 segment (OR, 1.05; 95 % CI, 1.01–1.10, per 0.01 increase in PI) and C4 segment (OR, 1.05; 95 % CI, 1.01–1.09) was positively associated with the dilation of basal ganglia PVS, and PI_flow in the ICA C4 segment (OR, 1.06, 95 % CI, 1.02–1.10) was correlated with the dilation of PVS in the white matter. ALPS was associated with PI_flow in the basilar artery (β, -0.273, p, 0.046) and PI_area in the ICA C2 (β, -0.239, p, 0.041) and C7 segments (β, -0.238, p, 0.037).

Conclusions

: Intracranial arterial pulsatility was associated with presumed neuroimaging markers of the glymphatic system, but the results were not consistent across different markers. Further studies are warranted to confirm these findings.

中文翻译：

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较高的颅内动脉搏动与推测的类淋巴系统成像标记物相关：一项探索性研究

背景

动脉搏动被认为是血管旁脑脊液流动的关键驱动因素，而血管旁脑脊液流动是类淋巴清除的基础。然而，尚未研究颅内动脉搏动是否与人类的类淋巴标记相关。

方法

七十三名社区参与者参加了这项研究。 4D 相衬磁共振成像 (MRI) 用于量化13 个主要脑内动脉段的血流动力学参数，包括血流搏动指数 (PI _flow ) 和面积搏动指数 (PI _area )。测量了三种推测的类淋巴系统神经影像标志物：包括血管周围空间的扩张（PVS）、沿血管周围空间的扩散率（ALPS）和白质中自由水的体积分数（FW）。我们探讨了 PI_面积、PI_流量和假定的类淋巴标记之间的关系，并控制了相关协变量。

结果

颈内动脉 (ICA) C2 段（OR，1.05；95% CI，1.01–1.10，PI 每增加 0.01）和 C4 段（OR，1.05；95% CI，1.01–1.09）的 PI​​ 流量呈正_相关与基底节 PVS 的扩张相关，ICA C4 段的 PI_流量（OR，1.06，95% CI，1.02-1.10）与白质中 PVS 的扩张相关。 ALPS 与基底动脉 (β, -0.273, p, 0.046) 中的 PI_血流以及ICA C2 (β, -0.239, p , 0.041) 和 C7 段 (β, -0.238, p , 0.037)中的 PI_区域相关。

结论

：颅内动脉搏动与推测的类淋巴系统神经影像标记物相关，但不同标记物的结果并不一致。需要进一步的研究来证实这些发现。