Superviscous properties of the in vivo brain at large scales
Herthum H, Dempsey SCH, Samani A, Schrank F, Shahryari M, Warmuth C, Tzschatzsch H, Braun J, Sack I (2021)
Publication Type: Journal article
Publication year: 2021
Journal
Book Volume: 121
Pages Range: 393-404
DOI: 10.1016/j.actbio.2020.12.027
Abstract
There is growing awareness that brain mechanical properties are important for neural development and health. However, published values of brain stiffness differ by orders of magnitude between static measurements and in vivo magnetic resonance elastography (MRE), which covers a dynamic range over several frequency decades. We here show that there is no fundamental disparity between static mechanical tests and in vivo MRE when considering large-scale properties, which encompass the entire brain including fluid filled compartments. Using gradient echo real-time MRE, we investigated the viscoelastic dispersion of the human brain in, so far, unexplored dynamic ranges from intrinsic brain pulsations at 1 Hz to ultralow-frequency vibrations at 5, 6.25, 7.8 and 10 Hz to the normal frequency range of MRE of 40 Hz. Surprisingly, we observed variations in brain stiffness over more than two orders of magnitude, suggesting that the in vivo human brain is superviscous on large scales with very low shear modulus of 42±13 Pa and relatively high viscosity of 6.6±0.3 Pa∙s according to the two-parameter solid model. Our data shed light on the crucial role of fluid compartments including blood vessels and cerebrospinal fluid (CSF) for whole brain properties and provide, for the first time, an explanation for the variability of the mechanical brain responses to manual palpation, local indentation, and high-dynamic tissue stimulation as used in elastography.
Involved external institutions
Charité - Universitätsmedizin Berlin
Germany (DE)
Western University
Canada (CA)
Freie Universität Berlin
Germany (DE)
Germany (DE)
Western University
Canada (CA)
Freie Universität Berlin
Germany (DE)
How to cite
APA:
Herthum, H., Dempsey, S.C.H., Samani, A., Schrank, F., Shahryari, M., Warmuth, C.,... Sack, I. (2021). Superviscous properties of the in vivo brain at large scales. Acta Biomaterialia, 121, 393-404. https://doi.org/10.1016/j.actbio.2020.12.027
MLA:
Herthum, Helge, et al. "Superviscous properties of the in vivo brain at large scales." Acta Biomaterialia 121 (2021): 393-404.
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