Susceptibility and size quantification of small human veins from an MRI method.
Susceptibility and size quantification of small human veins from an MRI method.
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DOI：
10.1016/j.mri.2015.07.008
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发表时间：
2015-12
影响因子：
2.5
通讯作者：
Neelavalli J
中科院分区：
文献类型：
--
作者：
Hsieh CY;Cheng YN;Xie H;Haacke EM;Neelavalli J
近年来，提出了一种利用典型的双回波梯度回波序列精确量化任意方向上任意窄圆柱形物体的磁化率和半径的方法，称为CISSCO （Complex Image Summation around a Spherical or a圆柱形物体）。本工作进一步优化了定量人脑小静脉血氧饱和度的方法。首先通过数值模拟验证了改进的方法，然后将其应用于幻影和人脑数据。研究了相位高通滤波对量化参数的影响，并提出了减轻其不利影响的方法。利用误差传播法估计了每次测量的不确定度。结果表明，即使在静脉中信噪比（信噪比）较低的情况下，修订后的方法也可以准确量化血管大小和氧饱和度。结果在给定受试者的不同静脉中是自一致的，变化小于6%。最后，提出了准确定量人体小静脉敏感性和半径的成像参数和方法。
Recently a method called CISSCO (Complex Image Summation around a Spherical or a Cylindrical Object) was introduced for accurately quantifying the susceptibility and the radius of any narrow cylindrical object at any orientation using a typical two-echo gradient echo sequence. This work further optimizes the method for quantifying oxygen saturation in small cerebral veins in the human brain. The revised method is first validated through numerical simulations and then applied to data from phantom and human brain. The effect of phase high pass filtering on the quantified parameters is studied and procedures for mitigating its adverse effects are suggested. Uncertainty of each measurement is estimated from the error propagation method. It is shown that the revised method allows for accurate quantification of both the vessel size and its oxygen saturation even in the case of a low SNR (signal to noise ratio) in the vein. The results are self consistent across different veins within a given subject with a variation of less than 6%. Finally, imaging parameters and some procedures are suggested for accurate susceptibility and radius quantifications of small human veins.