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A time-dependent diffusion MRI signature of axon caliber variations and beading
MRI provides a unique non-invasive window into the brain, yet is limited to millimeter resolution, orders of magnitude coarser than cell dimensions. Here, we show that diffusion MRI is sensitive to the micrometer-scale variations in axon caliber or pathological beading, by identifying a signature po...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group UK
2020
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7341838/ https://www.ncbi.nlm.nih.gov/pubmed/32636463 http://dx.doi.org/10.1038/s42003-020-1050-x |
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author | Lee, Hong-Hsi Papaioannou, Antonios Kim, Sung-Lyoung Novikov, Dmitry S. Fieremans, Els |
author_facet | Lee, Hong-Hsi Papaioannou, Antonios Kim, Sung-Lyoung Novikov, Dmitry S. Fieremans, Els |
author_sort | Lee, Hong-Hsi |
collection | PubMed |
description | MRI provides a unique non-invasive window into the brain, yet is limited to millimeter resolution, orders of magnitude coarser than cell dimensions. Here, we show that diffusion MRI is sensitive to the micrometer-scale variations in axon caliber or pathological beading, by identifying a signature power-law diffusion time-dependence of the along-fiber diffusion coefficient. We observe this signature in human brain white matter and identify its origins by Monte Carlo simulations in realistic substrates from 3-dimensional electron microscopy of mouse corpus callosum. Simulations reveal that the time-dependence originates from axon caliber variation, rather than from mitochondria or axonal undulations. We report a decreased amplitude of time-dependence in multiple sclerosis lesions, illustrating the potential sensitivity of our method to axonal beading in a plethora of neurodegenerative disorders. This specificity to microstructure offers an exciting possibility of bridging across scales to image cellular-level pathology with a clinically feasible MRI technique. |
format | Online Article Text |
id | pubmed-7341838 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | Nature Publishing Group UK |
record_format | MEDLINE/PubMed |
spelling | pubmed-73418382020-07-09 A time-dependent diffusion MRI signature of axon caliber variations and beading Lee, Hong-Hsi Papaioannou, Antonios Kim, Sung-Lyoung Novikov, Dmitry S. Fieremans, Els Commun Biol Article MRI provides a unique non-invasive window into the brain, yet is limited to millimeter resolution, orders of magnitude coarser than cell dimensions. Here, we show that diffusion MRI is sensitive to the micrometer-scale variations in axon caliber or pathological beading, by identifying a signature power-law diffusion time-dependence of the along-fiber diffusion coefficient. We observe this signature in human brain white matter and identify its origins by Monte Carlo simulations in realistic substrates from 3-dimensional electron microscopy of mouse corpus callosum. Simulations reveal that the time-dependence originates from axon caliber variation, rather than from mitochondria or axonal undulations. We report a decreased amplitude of time-dependence in multiple sclerosis lesions, illustrating the potential sensitivity of our method to axonal beading in a plethora of neurodegenerative disorders. This specificity to microstructure offers an exciting possibility of bridging across scales to image cellular-level pathology with a clinically feasible MRI technique. Nature Publishing Group UK 2020-07-07 /pmc/articles/PMC7341838/ /pubmed/32636463 http://dx.doi.org/10.1038/s42003-020-1050-x Text en © The Author(s) 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. |
spellingShingle | Article Lee, Hong-Hsi Papaioannou, Antonios Kim, Sung-Lyoung Novikov, Dmitry S. Fieremans, Els A time-dependent diffusion MRI signature of axon caliber variations and beading |
title | A time-dependent diffusion MRI signature of axon caliber variations and beading |
title_full | A time-dependent diffusion MRI signature of axon caliber variations and beading |
title_fullStr | A time-dependent diffusion MRI signature of axon caliber variations and beading |
title_full_unstemmed | A time-dependent diffusion MRI signature of axon caliber variations and beading |
title_short | A time-dependent diffusion MRI signature of axon caliber variations and beading |
title_sort | time-dependent diffusion mri signature of axon caliber variations and beading |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7341838/ https://www.ncbi.nlm.nih.gov/pubmed/32636463 http://dx.doi.org/10.1038/s42003-020-1050-x |
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