Human Whole Blood T2 Relaxometry at 3 Tesla
Human Whole Blood T2 Relaxometry at 3 Tesla
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DOI：
10.1002/mrm.21858
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发表时间：
2009-02-01
影响因子：
3.3
通讯作者：
Pike, G. Bruce
中科院分区：
文献类型：
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作者：
Chen, Jean J.;Pike, G. Bruce
精确了解人体血液自旋-自旋弛豫对许多应用非常重要，特别是功能性磁共振成像（fMRI），它越来越多地在3特斯拉下进行。众所周知，从部分脱氧血液中测量的T-2取决于Carr-Purcell Melboom-Gill（CPMG）再聚焦间隔（tau（180））和血氧（Y），但对这种现象的量化仍存在争议，主要是关于扩散和快速双位点交换模型表征的准确性。在本研究中，在3 T下对人全血中脱氧诱导的T-2减少进行了详细表征，并对tau（180）的作用进行了全面评估。扩散模型被认为是更好地拟合所观察到的T-2行为相比，交换模型。估计的扩散模型参数表明，在3 T的T2衰减增强是由于脱氧诱导的场不均匀性与场强的幅度线性增加。这些发现也证实了tau（180）操纵在测量静脉血容量变化方面的潜力。Magn Reson Mad 61：249-254，2009. (c)2009威利-利斯公司
A precise understanding of human blood spin-spin relaxation is of major importance for numerous applications, particularly functional magnetic resonance imaging (fMRI), which is increasingly performed at 3 Tesla. It is well known that T-2 measured from partially deoxygenated blood depends on the Carr-Purcell Melboom-Gill (CPMG) refocusing interval (tau(180)) and on blood oxygenation (Y), yet debate remains over the quantification of this phenomenon, primarily with respect to the accuracy of its characterization by the diffusion and fast two-site exchange models. In this study, a detailed characterization of the deoxygenation-induced T-2 reduction in human whole blood, as well as a comprehensive assessment of the role of tau(180), were performed at 3 T. The diffusion model was found to better fit the observed T-2 behavior as compared with the exchange model. The estimated diffusion-model parameters suggest the T2 decay enhancement at 3 T is due to a linear increase in the magnitude of deoxygenation-induced field inhomogeneities with field strength. These findings also confirm the potential of tau(180) manipulation in measuring changes in venous blood volume. Magn Reson Mad 61:249-254, 2009. (c) 2009 Wiley-Liss, Inc.