Field strength dependence of grey matter R2* on venous oxygenation
The relationship between venous blood oxygenation and change in transverse relaxation rate (ΔR2 *) plays a key role in calibrated BOLD fMRI. This relationship, defined by the parameter β, has previously been determined using theoretical simulations and experimental measures. However, these earlier s...
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| Format: | Article |
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Elsevier
2016
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| Online Access: | https://eprints.nottingham.ac.uk/37609/ |
| _version_ | 1848795496524546048 |
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| author | Croal, Paula L. Driver, Ian D. Francis, Susan T. Gowland, Penny A. |
| author_facet | Croal, Paula L. Driver, Ian D. Francis, Susan T. Gowland, Penny A. |
| author_sort | Croal, Paula L. |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | The relationship between venous blood oxygenation and change in transverse relaxation rate (ΔR2 *) plays a key role in calibrated BOLD fMRI. This relationship, defined by the parameter β, has previously been determined using theoretical simulations and experimental measures. However, these earlier studies have been confounded by the change in venous cerebral blood volume (CBV) in response to functional tasks. This study used a double-echo gradient echo EPI scheme in conjunction with a graded isocapnic hyperoxic sequence to assess quantitatively the relationship between the fractional venous blood oxygenation (1-Yv) and transverse relaxation rate of grey matter (ΔR2 * GM), without inducing a change in vCBV.
The results demonstrate that the relationship between ΔR2 * and fractional venous oxygenation at all magnet field strengths studied was adequately described by a linear relationship. The gradient of this relationship did not increase monotonically with field strength, which may be attributed to the relative contributions of intravascular and extravascular signals which will vary with both field strength and blood oxygenation. |
| first_indexed | 2025-11-14T19:33:01Z |
| format | Article |
| id | nottingham-37609 |
| institution | University of Nottingham Malaysia Campus |
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| last_indexed | 2025-11-14T19:33:01Z |
| publishDate | 2016 |
| publisher | Elsevier |
| recordtype | eprints |
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| spelling | nottingham-376092020-05-04T18:17:55Z https://eprints.nottingham.ac.uk/37609/ Field strength dependence of grey matter R2* on venous oxygenation Croal, Paula L. Driver, Ian D. Francis, Susan T. Gowland, Penny A. The relationship between venous blood oxygenation and change in transverse relaxation rate (ΔR2 *) plays a key role in calibrated BOLD fMRI. This relationship, defined by the parameter β, has previously been determined using theoretical simulations and experimental measures. However, these earlier studies have been confounded by the change in venous cerebral blood volume (CBV) in response to functional tasks. This study used a double-echo gradient echo EPI scheme in conjunction with a graded isocapnic hyperoxic sequence to assess quantitatively the relationship between the fractional venous blood oxygenation (1-Yv) and transverse relaxation rate of grey matter (ΔR2 * GM), without inducing a change in vCBV. The results demonstrate that the relationship between ΔR2 * and fractional venous oxygenation at all magnet field strengths studied was adequately described by a linear relationship. The gradient of this relationship did not increase monotonically with field strength, which may be attributed to the relative contributions of intravascular and extravascular signals which will vary with both field strength and blood oxygenation. Elsevier 2016-10-05 Article PeerReviewed Croal, Paula L., Driver, Ian D., Francis, Susan T. and Gowland, Penny A. (2016) Field strength dependence of grey matter R2* on venous oxygenation. NeuroImage . ISSN 1095-9572 calibrated BOLD; fMRI; R2⁎ quantification; oxygenation; hyperoxia http://www.sciencedirect.com/science/article/pii/S1053811916305523 doi:10.1016/j.neuroimage.2016.10.004 doi:10.1016/j.neuroimage.2016.10.004 |
| spellingShingle | calibrated BOLD; fMRI; R2⁎ quantification; oxygenation; hyperoxia Croal, Paula L. Driver, Ian D. Francis, Susan T. Gowland, Penny A. Field strength dependence of grey matter R2* on venous oxygenation |
| title | Field strength dependence of grey matter R2* on venous oxygenation |
| title_full | Field strength dependence of grey matter R2* on venous oxygenation |
| title_fullStr | Field strength dependence of grey matter R2* on venous oxygenation |
| title_full_unstemmed | Field strength dependence of grey matter R2* on venous oxygenation |
| title_short | Field strength dependence of grey matter R2* on venous oxygenation |
| title_sort | field strength dependence of grey matter r2* on venous oxygenation |
| topic | calibrated BOLD; fMRI; R2⁎ quantification; oxygenation; hyperoxia |
| url | https://eprints.nottingham.ac.uk/37609/ https://eprints.nottingham.ac.uk/37609/ https://eprints.nottingham.ac.uk/37609/ |