Volume‐localized measurement of oxygen extraction fraction in the brain using MRI
PURPOSE:T2 -relaxation-under-spin-tagging (TRUST) is an MR technique for the non-invasive assessment of whole-brain cerebral oxygen extraction fraction (OEF), through measurement of the venous blood T2 relaxation time in the sagittal sinus. A key limitation of TRUST, however, is the lack of spatial...
| Main Authors: | , , , |
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| Format: | Journal article |
| Language: | English |
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Wiley
2019
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| _version_ | 1797052494875983872 |
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| author | O'Brien, C Okell, T Chiew, M Jezzard, P |
| author_facet | O'Brien, C Okell, T Chiew, M Jezzard, P |
| author_sort | O'Brien, C |
| collection | OXFORD |
| description | PURPOSE:T2 -relaxation-under-spin-tagging (TRUST) is an MR technique for the non-invasive assessment of whole-brain cerebral oxygen extraction fraction (OEF), through measurement of the venous blood T2 relaxation time in the sagittal sinus. A key limitation of TRUST, however, is the lack of spatial specificity of the measurement. We sought to develop a modified TRUST sequence, selective localized TRUST (SL-TRUST), having sensitivity to venous blood T2 within a targeted brain region, and therefore achieving spatially localized measurements of cerebral tissue OEF, while still retaining acquisition in the sagittal sinus. METHODS:A method for selective localization of TRUST sequence was developed, and the reproducibility of the technique was evaluated in healthy participants. Regional measurements were achieved for a single hemisphere and for a 3D-localized 70 × 70 × 80 mm3 tissue region using SL-TRUST and compared to a global TRUST measure. An additional measure of venous blood T1 in the sagittal sinus was used to estimate subject-specific hematocrit. Six subjects were scanned over 4 sessions, including intra-session repeat measurements. RESULTS:The average T2 in the sagittal sinus was found to be 60.8 ± 8.9, 62.7 ± 7.9, 64.6 ± 8.4, and 66.3 ± 10.3 ms (mean ± SD) for conventional TRUST, global SL-TRUST, hemispheric SL-TRUST, and 3D-localized SL-TRUST, respectively. Intra-, inter-session, and inter-subject coefficients of variation for OEF using SL-TRUST were found to be comparable and in some cases superior to those obtained using TRUST. CONCLUSION:OEF comparison of 2 contralateral regions was achievable in under 5 min suggesting SL-TRUST offers potential for quantifying regional OEF differences in both healthy and clinical populations. |
| first_indexed | 2024-03-06T18:32:22Z |
| format | Journal article |
| id | oxford-uuid:0a1a420d-6c74-44af-b91a-3c37bea3f53a |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T18:32:22Z |
| publishDate | 2019 |
| publisher | Wiley |
| record_format | dspace |
| spelling | oxford-uuid:0a1a420d-6c74-44af-b91a-3c37bea3f53a2022-03-26T09:22:00ZVolume‐localized measurement of oxygen extraction fraction in the brain using MRIJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:0a1a420d-6c74-44af-b91a-3c37bea3f53aEnglishSymplectic Elements at OxfordWiley2019O'Brien, COkell, TChiew, MJezzard, PPURPOSE:T2 -relaxation-under-spin-tagging (TRUST) is an MR technique for the non-invasive assessment of whole-brain cerebral oxygen extraction fraction (OEF), through measurement of the venous blood T2 relaxation time in the sagittal sinus. A key limitation of TRUST, however, is the lack of spatial specificity of the measurement. We sought to develop a modified TRUST sequence, selective localized TRUST (SL-TRUST), having sensitivity to venous blood T2 within a targeted brain region, and therefore achieving spatially localized measurements of cerebral tissue OEF, while still retaining acquisition in the sagittal sinus. METHODS:A method for selective localization of TRUST sequence was developed, and the reproducibility of the technique was evaluated in healthy participants. Regional measurements were achieved for a single hemisphere and for a 3D-localized 70 × 70 × 80 mm3 tissue region using SL-TRUST and compared to a global TRUST measure. An additional measure of venous blood T1 in the sagittal sinus was used to estimate subject-specific hematocrit. Six subjects were scanned over 4 sessions, including intra-session repeat measurements. RESULTS:The average T2 in the sagittal sinus was found to be 60.8 ± 8.9, 62.7 ± 7.9, 64.6 ± 8.4, and 66.3 ± 10.3 ms (mean ± SD) for conventional TRUST, global SL-TRUST, hemispheric SL-TRUST, and 3D-localized SL-TRUST, respectively. Intra-, inter-session, and inter-subject coefficients of variation for OEF using SL-TRUST were found to be comparable and in some cases superior to those obtained using TRUST. CONCLUSION:OEF comparison of 2 contralateral regions was achievable in under 5 min suggesting SL-TRUST offers potential for quantifying regional OEF differences in both healthy and clinical populations. |
| spellingShingle | O'Brien, C Okell, T Chiew, M Jezzard, P Volume‐localized measurement of oxygen extraction fraction in the brain using MRI |
| title | Volume‐localized measurement of oxygen extraction fraction in the brain using MRI |
| title_full | Volume‐localized measurement of oxygen extraction fraction in the brain using MRI |
| title_fullStr | Volume‐localized measurement of oxygen extraction fraction in the brain using MRI |
| title_full_unstemmed | Volume‐localized measurement of oxygen extraction fraction in the brain using MRI |
| title_short | Volume‐localized measurement of oxygen extraction fraction in the brain using MRI |
| title_sort | volume localized measurement of oxygen extraction fraction in the brain using mri |
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