Validation of Quantitative Estimation of Tissue Oxygen Extraction Fraction and Deoxygenated Blood Volume Fraction in Phantom and In Vivo Experiments by Using MRI
Validation of Quantitative Estimation of Tissue Oxygen Extraction Fraction and Deoxygenated Blood Volume Fraction in Phantom and In Vivo Experiments by Using MRI
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DOI：
10.1002/mrm.22274
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发表时间：
2010-04-01
影响因子：
3.3
通讯作者：
Reichenbach, Juergen R.
中科院分区：
文献类型：
--
作者：
Sedlacik, Jan;Reichenbach, Juergen R.
脑组织的血氧水平依赖信号可以通过由随机取向的无限长圆柱体形成的网络模型从理论上导出。通过体模和体内实验验证该模型仍然是研究的对象。将固体聚丙烯线浸入硅油中制成网状体模，基本上消除了自旋扩散的影响。通过独立的方法预先确定了弦网络的体积分数和磁性。对10名健康志愿者进行了测量，以进行体内演示。用圆柱网络模型对梯度回波采样的自旋回波信号进行了评价。我们发现两个网络表征参数脱氧血容量和氧提取分数之间存在很强的相互依赖性。在此，不同的脱氧血容量/氧提取分数值组能够同样好地描述所测量的信号。然而，通过将一个参数常数设置为预定值，可以获得其他参数的合理估计值。在体内演示中发现了相同的行为。圆柱网络的信号理论通过良好表征的体模进行了验证。然而，发现脱氧血容量和氧提取分数之间的相互依赖性需要一个变量的独立估计，以确定其他参数的可靠值。Magn Reson Med 63：910-921，2010。(C)2010 Wiley-Liss，Inc.
The blood oxygenation level dependent signal of cerebral tissue can be theoretically derived using a network model formed by randomly oriented infinitely long cylinders. The validation of this model by phantom and in vivo experiments is still an object of research. A network phantom was constructed of solid polypropylene strings immersed in silicone oil, which essentially eliminated the effect of spin diffusion. The volume fraction and magnetic property of the string network was predetermined by independent methods. Ten healthy volunteers were measured for in vivo demonstration. The gradient echo sampled spin echo signal was evaluated with the cylinder network model. We found a strong interdependency between the two network characterizing parameters deoxygenated blood volume and oxygen extraction fraction. Here, different sets of deoxygenated blood volume/oxygen extraction fraction values were able to describe the measured signal equally well. However, by setting one parameter constant to a predetermined value, reasonable estimates of the other parameter were obtained. The same behavior was found for the in vivo demonstration. The signal theory of the cylinder network was validated by a well-characterized phantom. However, the found interdependency that was found between deoxygenated blood volume and oxygen extraction fraction requires an independent estimation of one variable to determine reliable values of the other parameter. Magn Reson Med 63:910-921, 2010. (C) 2010 Wiley-Liss, Inc.