Whole-brain 3D mapping of oxygen metabolism using constrained quantitative BOLD
Quantitative BOLD (qBOLD) MRI permits noninvasive evaluation of hemodynamic and metabolic states of the brain by quantifying parametric maps of deoxygenated blood volume (DBV) and hemoglobin oxygen saturation level of venous blood (Yv), and along with a measurement of cerebral blood flow (CBF), the...
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| Format: | Article |
| Language: | English |
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Elsevier
2022-04-01
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| Series: | NeuroImage |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S1053811922000817 |
| _version_ | 1819279417105448960 |
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| author | Hyunyeol Lee Felix W Wehrli |
| author_facet | Hyunyeol Lee Felix W Wehrli |
| author_sort | Hyunyeol Lee |
| collection | DOAJ |
| description | Quantitative BOLD (qBOLD) MRI permits noninvasive evaluation of hemodynamic and metabolic states of the brain by quantifying parametric maps of deoxygenated blood volume (DBV) and hemoglobin oxygen saturation level of venous blood (Yv), and along with a measurement of cerebral blood flow (CBF), the cerebral metabolic rate of oxygen (CMRO2). The method, thus should have potential to provide important information on many neurological disorders as well as normal cerebral physiology. One major challenge in qBOLD is to separate deoxyhemoglobin's contribution to R2′ from other sources modulating the voxel signal, for instance, R2, R2′ from non-heme iron (R′2,nh), and macroscopic magnetic field variations. Further, even with successful separation of the several confounders, it is still challenging to extract DBV and Yv from the heme-originated R2′ because of limited sensitivity of the qBOLD model. These issues, which have not been fully addressed in currently practiced qBOLD methods, have so far precluded 3D whole-brain implementation of qBOLD. Thus, the purpose of this work was to develop a new 3D MRI oximetry technique that enables robust qBOLD parameter mapping across the entire brain. To achieve this goal, we employed a rapid, R2′-sensitive, steady-state 3D pulse sequence (termed ‘AUSFIDE’) for data acquisition, and implemented a prior-constrained qBOLD processing pipeline that exploits a plurality of preliminary parameters obtained via AUSFIDE, along with additionally measured cerebral venous blood volume. Numerical simulations and in vivo studies at 3 T were performed to evaluate the performance of the proposed, constrained qBOLD mapping in comparison to the parent qBOLD method. Measured parameters (Yv, DBV, R′2,nh, nonblood magnetic susceptibility) in ten healthy subjects demonstrate the expected contrast across brain territories, while yielding group-averages of 64.0 ± 2.3 % and 62.2 ± 3.1 % for Yv and 2.8 ± 0.5 % and 1.8 ± 0.4 % for DBV in cortical gray and white matter, respectively. Given the Yv measurements, additionally quantified CBF in seven of the ten study subjects enabled whole-brain 3D CMRO2 mapping, yielding group averages of 134.2 ± 21.1 and 79.4 ± 12.6 μmol/100 g/min for cortical gray and white matter, in good agreement with literature values. The results suggest feasibility of the proposed method as a practical and reliable means for measuring neurometabolic parameters over an extended brain coverage. |
| first_indexed | 2024-12-24T00:27:34Z |
| format | Article |
| id | doaj.art-b2fb36404cbf4297981de5e57b255990 |
| institution | Directory Open Access Journal |
| issn | 1095-9572 |
| language | English |
| last_indexed | 2024-12-24T00:27:34Z |
| publishDate | 2022-04-01 |
| publisher | Elsevier |
| record_format | Article |
| series | NeuroImage |
| spelling | doaj.art-b2fb36404cbf4297981de5e57b2559902022-12-21T17:24:24ZengElsevierNeuroImage1095-95722022-04-01250118952Whole-brain 3D mapping of oxygen metabolism using constrained quantitative BOLDHyunyeol Lee0Felix W Wehrli1Laboratory for Structural, Physiologic, and Functional Imaging, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States; School of Electronics Engineering, Kyungpook National University, Daegu, South KoreaLaboratory for Structural, Physiologic, and Functional Imaging, Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States; Corresponding author.Quantitative BOLD (qBOLD) MRI permits noninvasive evaluation of hemodynamic and metabolic states of the brain by quantifying parametric maps of deoxygenated blood volume (DBV) and hemoglobin oxygen saturation level of venous blood (Yv), and along with a measurement of cerebral blood flow (CBF), the cerebral metabolic rate of oxygen (CMRO2). The method, thus should have potential to provide important information on many neurological disorders as well as normal cerebral physiology. One major challenge in qBOLD is to separate deoxyhemoglobin's contribution to R2′ from other sources modulating the voxel signal, for instance, R2, R2′ from non-heme iron (R′2,nh), and macroscopic magnetic field variations. Further, even with successful separation of the several confounders, it is still challenging to extract DBV and Yv from the heme-originated R2′ because of limited sensitivity of the qBOLD model. These issues, which have not been fully addressed in currently practiced qBOLD methods, have so far precluded 3D whole-brain implementation of qBOLD. Thus, the purpose of this work was to develop a new 3D MRI oximetry technique that enables robust qBOLD parameter mapping across the entire brain. To achieve this goal, we employed a rapid, R2′-sensitive, steady-state 3D pulse sequence (termed ‘AUSFIDE’) for data acquisition, and implemented a prior-constrained qBOLD processing pipeline that exploits a plurality of preliminary parameters obtained via AUSFIDE, along with additionally measured cerebral venous blood volume. Numerical simulations and in vivo studies at 3 T were performed to evaluate the performance of the proposed, constrained qBOLD mapping in comparison to the parent qBOLD method. Measured parameters (Yv, DBV, R′2,nh, nonblood magnetic susceptibility) in ten healthy subjects demonstrate the expected contrast across brain territories, while yielding group-averages of 64.0 ± 2.3 % and 62.2 ± 3.1 % for Yv and 2.8 ± 0.5 % and 1.8 ± 0.4 % for DBV in cortical gray and white matter, respectively. Given the Yv measurements, additionally quantified CBF in seven of the ten study subjects enabled whole-brain 3D CMRO2 mapping, yielding group averages of 134.2 ± 21.1 and 79.4 ± 12.6 μmol/100 g/min for cortical gray and white matter, in good agreement with literature values. The results suggest feasibility of the proposed method as a practical and reliable means for measuring neurometabolic parameters over an extended brain coverage.http://www.sciencedirect.com/science/article/pii/S1053811922000817Quantitative BOLD3DConstrained inverse problemBrain metabolismHemoglobin oxygen saturationCerebral metabolic rate of oxygen |
| spellingShingle | Hyunyeol Lee Felix W Wehrli Whole-brain 3D mapping of oxygen metabolism using constrained quantitative BOLD NeuroImage Quantitative BOLD 3D Constrained inverse problem Brain metabolism Hemoglobin oxygen saturation Cerebral metabolic rate of oxygen |
| title | Whole-brain 3D mapping of oxygen metabolism using constrained quantitative BOLD |
| title_full | Whole-brain 3D mapping of oxygen metabolism using constrained quantitative BOLD |
| title_fullStr | Whole-brain 3D mapping of oxygen metabolism using constrained quantitative BOLD |
| title_full_unstemmed | Whole-brain 3D mapping of oxygen metabolism using constrained quantitative BOLD |
| title_short | Whole-brain 3D mapping of oxygen metabolism using constrained quantitative BOLD |
| title_sort | whole brain 3d mapping of oxygen metabolism using constrained quantitative bold |
| topic | Quantitative BOLD 3D Constrained inverse problem Brain metabolism Hemoglobin oxygen saturation Cerebral metabolic rate of oxygen |
| url | http://www.sciencedirect.com/science/article/pii/S1053811922000817 |
| work_keys_str_mv | AT hyunyeollee wholebrain3dmappingofoxygenmetabolismusingconstrainedquantitativebold AT felixwwehrli wholebrain3dmappingofoxygenmetabolismusingconstrainedquantitativebold |