Quantifying MRI frequency shifts due to structures with anisotropic magnetic susceptibility using pyrolytic graphite sheet
Magnetic susceptibility is an important source of contrast in magnetic resonance imaging (MRI), with spatial variations in the susceptibility of tissue affecting both the magnitude and phase of the measured signals. This contrast has generally been interpreted by assuming that tissues have isotropic...
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| Format: | Article |
| Language: | English |
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Nature Publishing Group
2018
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| Online Access: | https://eprints.nottingham.ac.uk/50714/ |
| _version_ | 1848798321884266496 |
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| author | Cronin, Matthew Bowtell, Richard W. |
| author_facet | Cronin, Matthew Bowtell, Richard W. |
| author_sort | Cronin, Matthew |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | Magnetic susceptibility is an important source of contrast in magnetic resonance imaging (MRI), with spatial variations in the susceptibility of tissue affecting both the magnitude and phase of the measured signals. This contrast has generally been interpreted by assuming that tissues have isotropic magnetic susceptibility, but recent work has shown that the anisotropic magnetic susceptibility of ordered biological tissues, such as myelinated nerves and cardiac muscle fibers, gives rise to unexpected image contrast. This behavior occurs because the pattern of field variation generated by microstructural elements formed from material of anisotropic susceptibility can be very different from that predicted by modelling the effects in terms of isotropic susceptibility. In MR images of tissue, such elements are manifested at a sub-voxel length-scale, so the patterns of field variation that they generate cannot be directly visualized. Here, we used pyrolytic graphite sheet which has a large magnetic susceptibility anisotropy to form structures of known geometry with sizes large enough that the pattern of field variation could be mapped directly using MRI. This allowed direct validation of theoretical expressions describing the pattern of field variation from anisotropic structures with biologically relevant shapes (slabs, spherical shells and cylindrical shells). |
| first_indexed | 2025-11-14T20:17:55Z |
| format | Article |
| id | nottingham-50714 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T20:17:55Z |
| publishDate | 2018 |
| publisher | Nature Publishing Group |
| recordtype | eprints |
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| spelling | nottingham-507142020-05-08T12:00:22Z https://eprints.nottingham.ac.uk/50714/ Quantifying MRI frequency shifts due to structures with anisotropic magnetic susceptibility using pyrolytic graphite sheet Cronin, Matthew Bowtell, Richard W. Magnetic susceptibility is an important source of contrast in magnetic resonance imaging (MRI), with spatial variations in the susceptibility of tissue affecting both the magnitude and phase of the measured signals. This contrast has generally been interpreted by assuming that tissues have isotropic magnetic susceptibility, but recent work has shown that the anisotropic magnetic susceptibility of ordered biological tissues, such as myelinated nerves and cardiac muscle fibers, gives rise to unexpected image contrast. This behavior occurs because the pattern of field variation generated by microstructural elements formed from material of anisotropic susceptibility can be very different from that predicted by modelling the effects in terms of isotropic susceptibility. In MR images of tissue, such elements are manifested at a sub-voxel length-scale, so the patterns of field variation that they generate cannot be directly visualized. Here, we used pyrolytic graphite sheet which has a large magnetic susceptibility anisotropy to form structures of known geometry with sizes large enough that the pattern of field variation could be mapped directly using MRI. This allowed direct validation of theoretical expressions describing the pattern of field variation from anisotropic structures with biologically relevant shapes (slabs, spherical shells and cylindrical shells). Nature Publishing Group 2018-04-19 Article PeerReviewed application/pdf en cc_by https://eprints.nottingham.ac.uk/50714/7/s41598-018-24650-2.pdf Cronin, Matthew and Bowtell, Richard W. (2018) Quantifying MRI frequency shifts due to structures with anisotropic magnetic susceptibility using pyrolytic graphite sheet. Scientific Reports, 8 . 6259/1-6259/11. ISSN 2045-2322 https://www.nature.com/articles/s41598-018-24650-2 doi:10.1038/s41598-018-24650-2 doi:10.1038/s41598-018-24650-2 |
| spellingShingle | Cronin, Matthew Bowtell, Richard W. Quantifying MRI frequency shifts due to structures with anisotropic magnetic susceptibility using pyrolytic graphite sheet |
| title | Quantifying MRI frequency shifts due to structures with anisotropic magnetic susceptibility using pyrolytic graphite sheet |
| title_full | Quantifying MRI frequency shifts due to structures with anisotropic magnetic susceptibility using pyrolytic graphite sheet |
| title_fullStr | Quantifying MRI frequency shifts due to structures with anisotropic magnetic susceptibility using pyrolytic graphite sheet |
| title_full_unstemmed | Quantifying MRI frequency shifts due to structures with anisotropic magnetic susceptibility using pyrolytic graphite sheet |
| title_short | Quantifying MRI frequency shifts due to structures with anisotropic magnetic susceptibility using pyrolytic graphite sheet |
| title_sort | quantifying mri frequency shifts due to structures with anisotropic magnetic susceptibility using pyrolytic graphite sheet |
| url | https://eprints.nottingham.ac.uk/50714/ https://eprints.nottingham.ac.uk/50714/ https://eprints.nottingham.ac.uk/50714/ |