Contrast mechanisms associated with neuromelanin-MRI.
<h4>Purpose</h4> <p>To investigate the physical mechanisms associated with the contrast observed in neuromelanin-MRI.</p> <h4>Methods</h4> <p>Phantoms having different concentrations of synthetic melanins with different degrees of iron loading were examined...
| Main Authors: | , , , , , , , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
Wiley
2016
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| _version_ | 1797084618946510848 |
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| author | Trujillo, P Summers, PE Ferrari, E Zucca, FA Sturini, M Mainardi, LT Cerutti, S Smith, AK Smith, SA Zecca, L Costa, A |
| author_facet | Trujillo, P Summers, PE Ferrari, E Zucca, FA Sturini, M Mainardi, LT Cerutti, S Smith, AK Smith, SA Zecca, L Costa, A |
| author_sort | Trujillo, P |
| collection | OXFORD |
| description | <h4>Purpose</h4> <p>To investigate the physical mechanisms associated with the contrast observed in neuromelanin-MRI.</p> <h4>Methods</h4> <p>Phantoms having different concentrations of synthetic melanins with different degrees of iron loading were examined on a 3T scanner using relaxometry and quantitative magnetization transfer (MT).</p> <h4>Results</h4> <p>Concentration-dependent T1- and T2-shortening was most pronounced for the melanin pigment when combined with iron. Metal-free melanin had a negligible effect on the magnetization transfer spectra. On the contrary, the presence of iron-laden melanins resulted in a decreased magnetization transfer ratio. The presence of melanin or iron (or both) did not have a significant effect on the macromolecular content, represented by the pool size ratio.</p> <h4>Conclusion</h4> <p>The primary mechanism underlying contrast in neuromelanin-MRI seems to be the T1 reduction associated with melanin-iron complexes. The macromolecular content is not significantly influenced by the presence of melanin with or without iron, and thus the MT is not directly affected. However, as T1 plays a role in determining the MT-weighted signal, the magnetization transfer ratio is reduced in the presence of melanin-iron complexes.</p> |
| first_indexed | 2024-03-07T01:57:36Z |
| format | Journal article |
| id | oxford-uuid:9c428409-c86f-46f9-9a86-caff0dfc01e2 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T01:57:36Z |
| publishDate | 2016 |
| publisher | Wiley |
| record_format | dspace |
| spelling | oxford-uuid:9c428409-c86f-46f9-9a86-caff0dfc01e22022-03-27T00:34:45ZContrast mechanisms associated with neuromelanin-MRI.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:9c428409-c86f-46f9-9a86-caff0dfc01e2EnglishSymplectic Elements at OxfordWiley2016Trujillo, PSummers, PEFerrari, EZucca, FASturini, MMainardi, LTCerutti, SSmith, AKSmith, SAZecca, LCosta, A <h4>Purpose</h4> <p>To investigate the physical mechanisms associated with the contrast observed in neuromelanin-MRI.</p> <h4>Methods</h4> <p>Phantoms having different concentrations of synthetic melanins with different degrees of iron loading were examined on a 3T scanner using relaxometry and quantitative magnetization transfer (MT).</p> <h4>Results</h4> <p>Concentration-dependent T1- and T2-shortening was most pronounced for the melanin pigment when combined with iron. Metal-free melanin had a negligible effect on the magnetization transfer spectra. On the contrary, the presence of iron-laden melanins resulted in a decreased magnetization transfer ratio. The presence of melanin or iron (or both) did not have a significant effect on the macromolecular content, represented by the pool size ratio.</p> <h4>Conclusion</h4> <p>The primary mechanism underlying contrast in neuromelanin-MRI seems to be the T1 reduction associated with melanin-iron complexes. The macromolecular content is not significantly influenced by the presence of melanin with or without iron, and thus the MT is not directly affected. However, as T1 plays a role in determining the MT-weighted signal, the magnetization transfer ratio is reduced in the presence of melanin-iron complexes.</p> |
| spellingShingle | Trujillo, P Summers, PE Ferrari, E Zucca, FA Sturini, M Mainardi, LT Cerutti, S Smith, AK Smith, SA Zecca, L Costa, A Contrast mechanisms associated with neuromelanin-MRI. |
| title | Contrast mechanisms associated with neuromelanin-MRI. |
| title_full | Contrast mechanisms associated with neuromelanin-MRI. |
| title_fullStr | Contrast mechanisms associated with neuromelanin-MRI. |
| title_full_unstemmed | Contrast mechanisms associated with neuromelanin-MRI. |
| title_short | Contrast mechanisms associated with neuromelanin-MRI. |
| title_sort | contrast mechanisms associated with neuromelanin mri |
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