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Cerebral Ultrasound Time-Harmonic Elastography Reveals Softening of the Human Brain Due to Dehydration

Hydration influences blood volume, blood viscosity, and water content in soft tissues – variables that determine the biophysical properties of biological tissues including their stiffness. In the brain, the relationship between hydration and stiffness is largely unknown despite the increasing import...

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Autores principales: Kreft, Bernhard, Bergs, Judith, Shahryari, Mehrgan, Danyel, Leon Alexander, Hetzer, Stefan, Braun, Jürgen, Sack, Ingolf, Tzschätzsch, Heiko
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7830390/
https://www.ncbi.nlm.nih.gov/pubmed/33505319
http://dx.doi.org/10.3389/fphys.2020.616984
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author Kreft, Bernhard
Bergs, Judith
Shahryari, Mehrgan
Danyel, Leon Alexander
Hetzer, Stefan
Braun, Jürgen
Sack, Ingolf
Tzschätzsch, Heiko
author_facet Kreft, Bernhard
Bergs, Judith
Shahryari, Mehrgan
Danyel, Leon Alexander
Hetzer, Stefan
Braun, Jürgen
Sack, Ingolf
Tzschätzsch, Heiko
author_sort Kreft, Bernhard
collection PubMed
description Hydration influences blood volume, blood viscosity, and water content in soft tissues – variables that determine the biophysical properties of biological tissues including their stiffness. In the brain, the relationship between hydration and stiffness is largely unknown despite the increasing importance of stiffness as a quantitative imaging marker. In this study, we investigated cerebral stiffness (CS) in 12 healthy volunteers using ultrasound time-harmonic elastography (THE) in different hydration states: (i) during normal hydration, (ii) after overnight fasting, and (iii) within 1 h of drinking 12 ml of water per kg body weight. In addition, we correlated shear wave speed (SWS) with urine osmolality and hematocrit. SWS at normal hydration was 1.64 ± 0.02 m/s and decreased to 1.57 ± 0.04 m/s (p < 0.001) after overnight fasting. SWS increased again to 1.63 ± 0.01 m/s within 30 min of water drinking, returning to values measured during normal hydration (p = 0.85). Urine osmolality at normal hydration (324 ± 148 mOsm/kg) increased to 784 ± 107 mOsm/kg (p < 0.001) after fasting and returned to normal (288 ± 128 mOsm/kg, p = 0.83) after water drinking. SWS and urine osmolality correlated linearly (r = −0.68, p < 0.001), while SWS and hematocrit did not correlate (p = 0.31). Our results suggest that mild dehydration in the range of diurnal fluctuations is associated with significant softening of brain tissue, possibly due to reduced cerebral perfusion. To ensure consistency of results, it is important that cerebral elastography with a standardized protocol is performed during normal hydration.
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spelling pubmed-78303902021-01-26 Cerebral Ultrasound Time-Harmonic Elastography Reveals Softening of the Human Brain Due to Dehydration Kreft, Bernhard Bergs, Judith Shahryari, Mehrgan Danyel, Leon Alexander Hetzer, Stefan Braun, Jürgen Sack, Ingolf Tzschätzsch, Heiko Front Physiol Physiology Hydration influences blood volume, blood viscosity, and water content in soft tissues – variables that determine the biophysical properties of biological tissues including their stiffness. In the brain, the relationship between hydration and stiffness is largely unknown despite the increasing importance of stiffness as a quantitative imaging marker. In this study, we investigated cerebral stiffness (CS) in 12 healthy volunteers using ultrasound time-harmonic elastography (THE) in different hydration states: (i) during normal hydration, (ii) after overnight fasting, and (iii) within 1 h of drinking 12 ml of water per kg body weight. In addition, we correlated shear wave speed (SWS) with urine osmolality and hematocrit. SWS at normal hydration was 1.64 ± 0.02 m/s and decreased to 1.57 ± 0.04 m/s (p < 0.001) after overnight fasting. SWS increased again to 1.63 ± 0.01 m/s within 30 min of water drinking, returning to values measured during normal hydration (p = 0.85). Urine osmolality at normal hydration (324 ± 148 mOsm/kg) increased to 784 ± 107 mOsm/kg (p < 0.001) after fasting and returned to normal (288 ± 128 mOsm/kg, p = 0.83) after water drinking. SWS and urine osmolality correlated linearly (r = −0.68, p < 0.001), while SWS and hematocrit did not correlate (p = 0.31). Our results suggest that mild dehydration in the range of diurnal fluctuations is associated with significant softening of brain tissue, possibly due to reduced cerebral perfusion. To ensure consistency of results, it is important that cerebral elastography with a standardized protocol is performed during normal hydration. Frontiers Media S.A. 2021-01-11 /pmc/articles/PMC7830390/ /pubmed/33505319 http://dx.doi.org/10.3389/fphys.2020.616984 Text en Copyright © 2021 Kreft, Bergs, Shahryari, Danyel, Hetzer, Braun, Sack and Tzschätzsch. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Physiology
Kreft, Bernhard
Bergs, Judith
Shahryari, Mehrgan
Danyel, Leon Alexander
Hetzer, Stefan
Braun, Jürgen
Sack, Ingolf
Tzschätzsch, Heiko
Cerebral Ultrasound Time-Harmonic Elastography Reveals Softening of the Human Brain Due to Dehydration
title Cerebral Ultrasound Time-Harmonic Elastography Reveals Softening of the Human Brain Due to Dehydration
title_full Cerebral Ultrasound Time-Harmonic Elastography Reveals Softening of the Human Brain Due to Dehydration
title_fullStr Cerebral Ultrasound Time-Harmonic Elastography Reveals Softening of the Human Brain Due to Dehydration
title_full_unstemmed Cerebral Ultrasound Time-Harmonic Elastography Reveals Softening of the Human Brain Due to Dehydration
title_short Cerebral Ultrasound Time-Harmonic Elastography Reveals Softening of the Human Brain Due to Dehydration
title_sort cerebral ultrasound time-harmonic elastography reveals softening of the human brain due to dehydration
topic Physiology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7830390/
https://www.ncbi.nlm.nih.gov/pubmed/33505319
http://dx.doi.org/10.3389/fphys.2020.616984
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