MRI estimates of brain iron concentration in normal aging: Comparison of field-dependent (FDRI) and phase (SWI) methods
Different brain structures accumulate iron at different rates throughout the adult life span. Typically, striatal and brain stem structures are higher in iron concentrations in older than younger adults, whereas cortical white matter and thalamus have lower concentrations in the elderly than young a...
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| Format: | Article |
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Elsevier
2015
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| Online Access: | http://hdl.handle.net/1721.1/99702 https://orcid.org/0000-0002-7637-2914 |
| _version_ | 1826202763457986560 |
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| author | Pfefferbaum, Adolf Adalsteinsson, Elfar Rohlfing, Torsten Sullivan, Edith V. |
| author2 | Harvard University--MIT Division of Health Sciences and Technology |
| author_facet | Harvard University--MIT Division of Health Sciences and Technology Pfefferbaum, Adolf Adalsteinsson, Elfar Rohlfing, Torsten Sullivan, Edith V. |
| author_sort | Pfefferbaum, Adolf |
| collection | MIT |
| description | Different brain structures accumulate iron at different rates throughout the adult life span. Typically, striatal and brain stem structures are higher in iron concentrations in older than younger adults, whereas cortical white matter and thalamus have lower concentrations in the elderly than young adults. Brain iron can be measured in vivo with MRI by estimating the relaxivity increase across magnetic field strengths, which yields the Field-Dependent Relaxation Rate Increase (FDRI) metric. The influence of local iron deposition on susceptibility, manifests as MR phase effects, forms the basis for another approach for iron measurement, Susceptibility-Weighted Imaging (SWI), for which imaging at only one field strength is sufficient. Here, we compared the ability of these two methods to detect and quantify brain iron in 11 young (5 men, 6 women; 21 to 29 years) and 12 elderly (6 men, 6 women; 64 to 86 years) healthy adults. FDRI was acquired at 1.5 T and 3.0 T, and SWI was acquired at 1.5 T. The results showed that both methods detected high globus pallidus iron concentration regardless of age and significantly greater iron in putamen with advancing age. The SWI measures were more sensitive when the phase signal intensities themselves were used to define regions of interest, whereas FDRI measures were robust to the method of region of interest selection. Further, FDRI measures were more highly correlated than SWI iron estimates with published postmortem values and were more sensitive than SWI to iron concentration differences across basal ganglia structures. Whereas FDRI requires more imaging time than SWI, two field strengths, and across-study image registration for iron concentration calculation, FDRI appears more specific to age-dependent accumulation of non-heme brain iron than SWI, which is affected by heme iron and non-iron source effects on phase. |
| first_indexed | 2024-09-23T12:16:55Z |
| format | Article |
| id | mit-1721.1/99702 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T12:16:55Z |
| publishDate | 2015 |
| publisher | Elsevier |
| record_format | dspace |
| spelling | mit-1721.1/997022022-09-28T00:54:38Z MRI estimates of brain iron concentration in normal aging: Comparison of field-dependent (FDRI) and phase (SWI) methods Pfefferbaum, Adolf Adalsteinsson, Elfar Rohlfing, Torsten Sullivan, Edith V. Harvard University--MIT Division of Health Sciences and Technology Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science Adalsteinsson, Elfar Different brain structures accumulate iron at different rates throughout the adult life span. Typically, striatal and brain stem structures are higher in iron concentrations in older than younger adults, whereas cortical white matter and thalamus have lower concentrations in the elderly than young adults. Brain iron can be measured in vivo with MRI by estimating the relaxivity increase across magnetic field strengths, which yields the Field-Dependent Relaxation Rate Increase (FDRI) metric. The influence of local iron deposition on susceptibility, manifests as MR phase effects, forms the basis for another approach for iron measurement, Susceptibility-Weighted Imaging (SWI), for which imaging at only one field strength is sufficient. Here, we compared the ability of these two methods to detect and quantify brain iron in 11 young (5 men, 6 women; 21 to 29 years) and 12 elderly (6 men, 6 women; 64 to 86 years) healthy adults. FDRI was acquired at 1.5 T and 3.0 T, and SWI was acquired at 1.5 T. The results showed that both methods detected high globus pallidus iron concentration regardless of age and significantly greater iron in putamen with advancing age. The SWI measures were more sensitive when the phase signal intensities themselves were used to define regions of interest, whereas FDRI measures were robust to the method of region of interest selection. Further, FDRI measures were more highly correlated than SWI iron estimates with published postmortem values and were more sensitive than SWI to iron concentration differences across basal ganglia structures. Whereas FDRI requires more imaging time than SWI, two field strengths, and across-study image registration for iron concentration calculation, FDRI appears more specific to age-dependent accumulation of non-heme brain iron than SWI, which is affected by heme iron and non-iron source effects on phase. National Institutes of Health (U.S.) (Grant AG017919) National Institutes of Health (U.S.) (Grant AA005965) National Institutes of Health (U.S.) (Grant AA017168) 2015-11-04T13:55:20Z 2015-11-04T13:55:20Z 2009-05 2009-05 Article http://purl.org/eprint/type/JournalArticle 10538119 1095-9572 http://hdl.handle.net/1721.1/99702 Pfefferbaum, Adolf, Elfar Adalsteinsson, Torsten Rohlfing, and Edith V. Sullivan. “MRI Estimates of Brain Iron Concentration in Normal Aging: Comparison of Field-Dependent (FDRI) and Phase (SWI) Methods.” NeuroImage 47, no. 2 (August 2009): 493–500. https://orcid.org/0000-0002-7637-2914 en_US http://dx.doi.org/10.1016/j.neuroimage.2009.05.006 NeuroImage Creative Commons Attribution http://creativecommons.org/licenses/by-nc-nd/4.0/ application/pdf Elsevier PMC |
| spellingShingle | Pfefferbaum, Adolf Adalsteinsson, Elfar Rohlfing, Torsten Sullivan, Edith V. MRI estimates of brain iron concentration in normal aging: Comparison of field-dependent (FDRI) and phase (SWI) methods |
| title | MRI estimates of brain iron concentration in normal aging: Comparison of field-dependent (FDRI) and phase (SWI) methods |
| title_full | MRI estimates of brain iron concentration in normal aging: Comparison of field-dependent (FDRI) and phase (SWI) methods |
| title_fullStr | MRI estimates of brain iron concentration in normal aging: Comparison of field-dependent (FDRI) and phase (SWI) methods |
| title_full_unstemmed | MRI estimates of brain iron concentration in normal aging: Comparison of field-dependent (FDRI) and phase (SWI) methods |
| title_short | MRI estimates of brain iron concentration in normal aging: Comparison of field-dependent (FDRI) and phase (SWI) methods |
| title_sort | mri estimates of brain iron concentration in normal aging comparison of field dependent fdri and phase swi methods |
| url | http://hdl.handle.net/1721.1/99702 https://orcid.org/0000-0002-7637-2914 |
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