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Quantitative susceptibility mapping (QSM) as a means to measure brain iron? A post mortem validation study
Quantitative susceptibility mapping (QSM) is a novel technique which allows determining the bulk magnetic susceptibility distribution of tissue in vivo from gradient echo magnetic resonance phase images. It is commonly assumed that paramagnetic iron is the predominant source of susceptibility variat...
Autores principales: | , , , , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Academic Press
2012
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3413885/ https://www.ncbi.nlm.nih.gov/pubmed/22634862 http://dx.doi.org/10.1016/j.neuroimage.2012.05.049 |
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author | Langkammer, Christian Schweser, Ferdinand Krebs, Nikolaus Deistung, Andreas Goessler, Walter Scheurer, Eva Sommer, Karsten Reishofer, Gernot Yen, Kathrin Fazekas, Franz Ropele, Stefan Reichenbach, Jürgen R. |
author_facet | Langkammer, Christian Schweser, Ferdinand Krebs, Nikolaus Deistung, Andreas Goessler, Walter Scheurer, Eva Sommer, Karsten Reishofer, Gernot Yen, Kathrin Fazekas, Franz Ropele, Stefan Reichenbach, Jürgen R. |
author_sort | Langkammer, Christian |
collection | PubMed |
description | Quantitative susceptibility mapping (QSM) is a novel technique which allows determining the bulk magnetic susceptibility distribution of tissue in vivo from gradient echo magnetic resonance phase images. It is commonly assumed that paramagnetic iron is the predominant source of susceptibility variations in gray matter as many studies have reported a reasonable correlation of magnetic susceptibility with brain iron concentrations in vivo. Instead of performing direct comparisons, however, all these studies used the putative iron concentrations reported in the hallmark study by Hallgren and Sourander (1958) for their analysis. Consequently, the extent to which QSM can serve to reliably assess brain iron levels is not yet fully clear. To provide such information we investigated the relation between bulk tissue magnetic susceptibility and brain iron concentration in unfixed (in situ) post mortem brains of 13 subjects using MRI and inductively coupled plasma mass spectrometry. A strong linear correlation between chemically determined iron concentration and bulk magnetic susceptibility was found in gray matter structures (r = 0.84, p < 0.001), whereas the correlation coefficient was much lower in white matter (r = 0.27, p < 0.001). The slope of the overall linear correlation was consistent with theoretical considerations of the magnetism of ferritin supporting that most of the iron in the brain is bound to ferritin proteins. In conclusion, iron is the dominant source of magnetic susceptibility in deep gray matter and can be assessed with QSM. In white matter regions the estimation of iron concentrations by QSM is less accurate and more complex because the counteracting contribution from diamagnetic myelinated neuronal fibers confounds the interpretation. |
format | Online Article Text |
id | pubmed-3413885 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2012 |
publisher | Academic Press |
record_format | MEDLINE/PubMed |
spelling | pubmed-34138852012-09-01 Quantitative susceptibility mapping (QSM) as a means to measure brain iron? A post mortem validation study Langkammer, Christian Schweser, Ferdinand Krebs, Nikolaus Deistung, Andreas Goessler, Walter Scheurer, Eva Sommer, Karsten Reishofer, Gernot Yen, Kathrin Fazekas, Franz Ropele, Stefan Reichenbach, Jürgen R. Neuroimage Article Quantitative susceptibility mapping (QSM) is a novel technique which allows determining the bulk magnetic susceptibility distribution of tissue in vivo from gradient echo magnetic resonance phase images. It is commonly assumed that paramagnetic iron is the predominant source of susceptibility variations in gray matter as many studies have reported a reasonable correlation of magnetic susceptibility with brain iron concentrations in vivo. Instead of performing direct comparisons, however, all these studies used the putative iron concentrations reported in the hallmark study by Hallgren and Sourander (1958) for their analysis. Consequently, the extent to which QSM can serve to reliably assess brain iron levels is not yet fully clear. To provide such information we investigated the relation between bulk tissue magnetic susceptibility and brain iron concentration in unfixed (in situ) post mortem brains of 13 subjects using MRI and inductively coupled plasma mass spectrometry. A strong linear correlation between chemically determined iron concentration and bulk magnetic susceptibility was found in gray matter structures (r = 0.84, p < 0.001), whereas the correlation coefficient was much lower in white matter (r = 0.27, p < 0.001). The slope of the overall linear correlation was consistent with theoretical considerations of the magnetism of ferritin supporting that most of the iron in the brain is bound to ferritin proteins. In conclusion, iron is the dominant source of magnetic susceptibility in deep gray matter and can be assessed with QSM. In white matter regions the estimation of iron concentrations by QSM is less accurate and more complex because the counteracting contribution from diamagnetic myelinated neuronal fibers confounds the interpretation. Academic Press 2012-09 /pmc/articles/PMC3413885/ /pubmed/22634862 http://dx.doi.org/10.1016/j.neuroimage.2012.05.049 Text en © 2012 Elsevier Inc. https://creativecommons.org/licenses/by-nc-nd/3.0/ Open Access under CC BY-NC-ND 3.0 (https://creativecommons.org/licenses/by-nc-nd/3.0/) license |
spellingShingle | Article Langkammer, Christian Schweser, Ferdinand Krebs, Nikolaus Deistung, Andreas Goessler, Walter Scheurer, Eva Sommer, Karsten Reishofer, Gernot Yen, Kathrin Fazekas, Franz Ropele, Stefan Reichenbach, Jürgen R. Quantitative susceptibility mapping (QSM) as a means to measure brain iron? A post mortem validation study |
title | Quantitative susceptibility mapping (QSM) as a means to measure brain iron? A post mortem validation study |
title_full | Quantitative susceptibility mapping (QSM) as a means to measure brain iron? A post mortem validation study |
title_fullStr | Quantitative susceptibility mapping (QSM) as a means to measure brain iron? A post mortem validation study |
title_full_unstemmed | Quantitative susceptibility mapping (QSM) as a means to measure brain iron? A post mortem validation study |
title_short | Quantitative susceptibility mapping (QSM) as a means to measure brain iron? A post mortem validation study |
title_sort | quantitative susceptibility mapping (qsm) as a means to measure brain iron? a post mortem validation study |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3413885/ https://www.ncbi.nlm.nih.gov/pubmed/22634862 http://dx.doi.org/10.1016/j.neuroimage.2012.05.049 |
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