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- Knutsson, Linda, et al.
(författare)
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Dynamic susceptibility contrast MRI with a prebolus contrast agent administration design for improved absolute quantification of perfusion.
- 2014
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Ingår i: Magnetic Resonance in Medicine. - : Wiley. - 1522-2594 .- 0740-3194. ; 72:4, s. 996-1006
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Tidskriftsartikel (refereegranskat)abstract
- Arterial partial-volume effects (PVEs) often hamper reproducible absolute quantification of cerebral blood flow (CBF) and cerebral blood volume (CBV) obtained by dynamic susceptibility contrast MRI (DSC-MRI). The aim of this study was to examine whether arterial PVEs in DSC-MRI data can be minimized by rescaling the arterial input function (AIF) using a sagittal-sinus venous output function obtained following a prebolus administration of a low dose of contrast agent.
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| 4. |
- Kämpe, Robin, et al.
(författare)
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Quantification of normal cerebral oxygen extraction and oxygen metabolism by phase-based MRI susceptometry: evaluation of repeatability using two different imaging protocols.
- 2017
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Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961. ; 37:2, s. 220-2011
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Tidskriftsartikel (refereegranskat)abstract
- Global oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO2 ) were quantified in a test-retest study. Cerebral blood flow (CBF) data, required for CMRO2 estimation, were obtained using dynamic susceptibility contrast MRI (DSC-MRI). OEF and CMRO2 were quantified using two separate data sets, that is, conventional high-resolution (HR) gradient echo (GRE) phase maps as well as echo planar imaging (EPI) phase maps taken from the baseline (precontrast) part of the DSC-MRI time series. The EPI phase data were included to elucidate whether an extra HR-GRE scan is needed to obtain information about OEF and CMRO2 , or if this information can be extracted from the DSC-MRI experiment only.
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| 5. |
- Wirestam, Ronnie, et al.
(författare)
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Test-retest analysis of cerebral oxygen extraction estimates in healthy volunteers : comparison of methods based on quantitative susceptibility mapping and dynamic susceptibility contrast magnetic resonance imaging
- 2022
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Ingår i: Heliyon. - : Elsevier BV. - 2405-8440. ; 8:12
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Tidskriftsartikel (refereegranskat)abstract
- Background: Estimation of the oxygen extraction fraction (OEF) by quantitative susceptibility mapping (QSM) magnetic resonance imaging (MRI) is promising but requires systematic evaluation. Extraction of OEF-related information from the tissue residue function in dynamic susceptibility contrast MRI (DSC-MRI) has also been proposed. In this study, whole-brain OEF repeatability was investigated, as well as the relationships between QSM-based OEF and DSC-MRI-based parameters, i.e., mean transit time (MTT) and an oxygen extraction index, referred to as apparent OEF (AOEF). Method: Test-retest data were obtained from 20 healthy volunteers at 3 T. QSM maps were reconstructed from 3D gradient-echo MRI phase data, using morphology-enabled dipole inversion. DSC-MRI was accomplished using gradient-echo MRI at a temporal resolution of 1.24 s. Results: The whole-brain QSM-based OEF was (40.4±4.8) % and, in combination with a previously published cerebral blood flow (CBF) estimate, this corresponds to a cerebral metabolic rate of oxygen level of CMRO2 = 3.36 ml O2/min/100 g. The intra-class correlation coefficient [ICC(2,1)] for OEF test-retest data was 0.73. The MTT-versus-OEF and AOEF-versus-OEF relationships showed correlation coefficients of 0.61 (p = 0.004) and 0.52 (p = 0.019), respectively. Discussion: QSM-based OEF showed a convincing absolute level and good test-retest results in terms of the ICC. Moderate to good correlations between QSM-based OEF and DSC-MRI-based parameters were observed. The present results constitute an indicator of the level of robustness that can be achieved without applying extraordinary resources in terms of MRI equipment, imaging protocol, QSM reconstruction, and OEF analysis.
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