Two analytical solutions for a model of pulsed arterial spin labeling with randomized blood arrival times
Two analytical solutions for a model of pulsed arterial spin labeling with randomized blood arrival times
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DOI：
10.1016/j.jmr.2003.11.002
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发表时间：
2004-03-01
影响因子：
2.2
通讯作者：
Lewis, DP
中科院分区：
文献类型：
--
作者：
Hrabe, J;Lewis, DP
脉冲动脉自旋标记灌注方法的一个相当一般的理论模型已经有一段时间了，但只有少数动脉血输入函数的解析解。这些大多假设标记的血液突然且同时到达成像区域。更一般的情况下，必须处理数字。我们提出了两个更现实的动脉输入函数的解析解。它们都允许标记的动脉血分子的到达时间统计分布。我们考虑的情况下（1）均匀分布在有限的时间间隔和（2）正态分布的特点是其平均值和标准差。这些模型在生理上是有意义的，因为到达时间的统计性质反映了血液水分子从标记区域到成像区域的速度和路径长度的分布。模型参数可以根据测量的灌注信号对标签反转时间的依赖性来估计。(C)2003年爱思唯尔公司All rights reserved.
A fairly general theoretical model for pulsed arterial spin labeling perfusion methods has been available for some time but analytical solutions were derived for only a small number of arterial blood input functions. These mostly assumed a sudden and simultaneous arrival of the tagged blood into the imaged region. More general cases had to be handled numerically. We present analytical solutions for two more realistic arterial input functions. They both allow the arrival times of the molecules of tagged arterial blood to be statistically distributed. We consider cases of (1) a uniform distribution on a finite time interval and (2) a normal distribution characterized by its mean and standard deviation. These models are physiologically meaningful because the statistical nature of the arrival times reflects the distribution of velocities and path lengths that the blood water molecules undertake from the tagging region to the imaged region. The model parameters can be estimated from the measured dependency of the perfusion signal on the tag inversion time. (C) 2003 Elsevier Inc. All rights reserved.