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Vegard Vinje
Simula Research Laboratory AS
Corresponding Author
ORCiD: https://orcid.org/0000-0003-2928-3385
License:
This work is licensed under a CC BY 4.0 License. Read Full License
Background: Perivascular fluid flow, of cerebrospinal or interstitial fluid in spaces surrounding brain blood vessels, is recognized as a key component underlying brain transport and clearance. An important open question is how and to what extent differences in vessel type or geometry affect perivascular fluid flow and transport.
Methods: Using computational modelling in both idealized and image-based geometries, we study and compare fluid flow and solute transport in pial (surface) periarterial and perivenous spaces.
Results: Our findings demonstrate that differences in geometry between arterial and venous pial perivascular spaces (PVSs) lead to higher net CSF flow, more rapid tracer transport and earlier arrival times of injected tracers in periarterial spaces compared to perivenous spaces.
Conclusions: These findings can explain the experimentally observed rapid appearance of tracers around arteries, and the delayed appearance around veins without the need of a circulation through the parenchyma, but rather by direct transport along the PVSs.
Keywords
Perivascular space, Cerebrospinal fluid, Computational biology, Fluid mechanics
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The full text of this article is available to read as a PDF.
This is a list of supplementary files associated with this preprint. Click to download.
- AdditionalFile1.mp4
Additional file 1 (video): Perivascular flows resulting from a gradual change from periarterial to perivenous space.
- AdditionalFile2.mp4
Additional file 2 (video): Perivascular flows resulting from a gradual change in PVS widths.
- AdditionalFile3.png
Additional file 3 (figure): Numerical convergence study. Left: Concentration (AU) in idealized perivenous spaces vs time for different time resolutions ∆t = 10,5,2.5 s. Right: Concentration (AU) in idealized perivenous spaces vs time for different mesh resolutions (coarse, medium, fine). The refined meshes were constructed by uniform refinement of the original mesh. Simulation results are reported from the ’medium’ mesh and the coarsest time step.
- AdditionalFile4.png
Additional file 4 (figure): The "medium" mesh resolution on geometries A0 and V0 used to perform the simulations
- AdditionalFile5.mp4
Additional file 5 (video): Concentrations in idealized periarterial and perivenous geometries. A threshold of 0.7 was used to visualize the transport of tracer. Tracers appear earlier around periarterial spaces due to higher convective velocities.
- AdditionalFile6.mp4
Additional file 6 (video): Concentrations in image-based periarterial and perivenous geometries. A threshold of 0.7 was used to visualize the transport of tracer. Tracers appear earlier around periarterial spaces due to higher convective velocities.
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A new preprint design is coming!
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This is a preprint, a preliminary version of a manuscript that has not completed peer review at a journal. Research Square does not conduct peer review prior to posting preprints. The posting of a preprint on this server should not be interpreted as an endorsement of its validity or suitability for dissemination as established information or for guiding clinical practice.
Research
Vegard Vinje
Simula Research Laboratory AS
Corresponding Author
ORCiD: https://orcid.org/0000-0003-2928-3385
Badges
Prescreen
This manuscript passed our Prescreen assessment
Complete author information
Appropriate declaration statements
Potential risks to human health
Prescreen
History
CURRENT STATUS: Posted
Version 1
Posted 29 Mar, 2021
No community comments so far
Metrics
Comments: 0
PDF Downloads: ...
HTML Views: ...
License:
This work is licensed under a CC BY 4.0 License. Read Full License
Background: Perivascular fluid flow, of cerebrospinal or interstitial fluid in spaces surrounding brain blood vessels, is recognized as a key component underlying brain transport and clearance. An important open question is how and to what extent differences in vessel type or geometry affect perivascular fluid flow and transport.
Methods: Using computational modelling in both idealized and image-based geometries, we study and compare fluid flow and solute transport in pial (surface) periarterial and perivenous spaces.
Results: Our findings demonstrate that differences in geometry between arterial and venous pial perivascular spaces (PVSs) lead to higher net CSF flow, more rapid tracer transport and earlier arrival times of injected tracers in periarterial spaces compared to perivenous spaces.
Conclusions: These findings can explain the experimentally observed rapid appearance of tracers around arteries, and the delayed appearance around veins without the need of a circulation through the parenchyma, but rather by direct transport along the PVSs.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
The full text of this article is available to read as a PDF.
This is a list of supplementary files associated with this preprint. Click to download.
- AdditionalFile1.mp4
Additional file 1 (video): Perivascular flows resulting from a gradual change from periarterial to perivenous space.
- AdditionalFile2.mp4
Additional file 2 (video): Perivascular flows resulting from a gradual change in PVS widths.
- AdditionalFile3.png
Additional file 3 (figure): Numerical convergence study. Left: Concentration (AU) in idealized perivenous spaces vs time for different time resolutions ∆t = 10,5,2.5 s. Right: Concentration (AU) in idealized perivenous spaces vs time for different mesh resolutions (coarse, medium, fine). The refined meshes were constructed by uniform refinement of the original mesh. Simulation results are reported from the ’medium’ mesh and the coarsest time step.
- AdditionalFile4.png
Additional file 4 (figure): The "medium" mesh resolution on geometries A0 and V0 used to perform the simulations
- AdditionalFile5.mp4
Additional file 5 (video): Concentrations in idealized periarterial and perivenous geometries. A threshold of 0.7 was used to visualize the transport of tracer. Tracers appear earlier around periarterial spaces due to higher convective velocities.
- AdditionalFile6.mp4
Additional file 6 (video): Concentrations in image-based periarterial and perivenous geometries. A threshold of 0.7 was used to visualize the transport of tracer. Tracers appear earlier around periarterial spaces due to higher convective velocities.
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