Arterial pulsation dependence of perivascular cerebrospinal fluid flow measured by dynamic diffusion tensor imaging in the human brain

Bibliographic Details
Title: Arterial pulsation dependence of perivascular cerebrospinal fluid flow measured by dynamic diffusion tensor imaging in the human brain
Authors: Guangxu Han, Bingjie Jiao, Yifan Zhang, Zejun Wang, Chunjing Liang, Yong Li, Yi-Cheng Hsu, Ruiliang Bai
Source: NeuroImage, Vol 297, Iss , Pp 120653- (2024)
Publisher Information: Elsevier, 2024.
Publication Year: 2024
Collection: LCC:Neurosciences. Biological psychiatry. Neuropsychiatry
Subject Terms: Glymphatic system, Arterial pulsation, Cerebral spinal fluid, Perivascular space, Diffusion MRI, Neurosciences. Biological psychiatry. Neuropsychiatry, RC321-571
More Details: Perivascular cerebrospinal fluid (pCSF) flow is a key component of the glymphatic system. Arterial pulsation has been proposed as the main driving force of pCSF influx along the superficial and penetrating arteries; however, evidence of this mechanism in humans is limited. We proposed an experimental framework of dynamic diffusion tensor imaging with low b-values and ultra-long echo time (dynDTIlow-b) to capture pCSF flow properties during the cardiac cycle in human brains. Healthy adult volunteers (aged 17–28 years; seven men, one woman) underwent dynDTIlow-b using a 3T scanner (MAGNETOM Prisma, Siemens Healthcare, Erlangen, Germany) with simultaneously recorded cardiac output. The results showed that diffusion tensors reconstructed from pCSF were mainly oriented in the direction of the neighboring arterial flow. When switching from vasoconstriction to vasodilation, the axial and radial diffusivities of the pCSF increased by 5.7 % and 4.94 %, respectively, suggesting that arterial pulsation alters the pCSF flow both parallel and perpendicular to the arterial wall. DynDTIlow-b signal intensity at b=0 s/mm2 (i.e., T2-weighted, [S(b=0 s/mm2)]) decreased in systole, but this change was ∼7.5 % of a cardiac cycle slower than the changes in apparent diffusivity, suggesting that changes in S(b=0 s/mm2) and apparent diffusivity arise from distinct physiological processes and potential biomarkers associated with perivascular space volume and pCSF flow, respectively. Additionally, the mean diffusivities of white matter showed cardiac-cycle dependencies similar to pCSF, although a delay relative to the peak time of apparent diffusivity in pCSF was present, suggesting that dynDTIlow-b could potentially reveal the dynamics of magnetic resonance imaging-invisible pCSF surrounding small arteries and arterioles in white matter; this delay may result from pulse wave propagation along penetrating arteries. In conclusion, the vasodilation-induced increases in axial and radial diffusivities of pCSF and mean diffusivities of white matter are consistent with the notion that arterial pulsation can accelerate pCSF flow in human brain. Furthermore, the proposed dynDTIlow-b technique can capture various pCSF dynamics in artery pulsation.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 1095-9572
Relation: http://www.sciencedirect.com/science/article/pii/S1053811924001484; https://doaj.org/toc/1095-9572
DOI: 10.1016/j.neuroimage.2024.120653
Access URL: https://doaj.org/article/dc55ba3ac9c0486da1ccd10561bc63ca
Accession Number: edsdoj.55ba3ac9c0486da1ccd10561bc63ca
Database: Directory of Open Access Journals
More Details
ISSN:10959572
DOI:10.1016/j.neuroimage.2024.120653
Published in:NeuroImage
Language:English