Comparing Model-Based and Model-Free Analysis Methods for QUASAR Arterial Spin Labeling Perfusion Quantification
Comparing Model-Based and Model-Free Analysis Methods for QUASAR Arterial Spin Labeling Perfusion Quantification
复制标题
DOI：
10.1002/mrm.24372
复制
发表时间：
2013-05-01
影响因子：
3.3
通讯作者：
Payne, Stephen J.
中科院分区：
文献类型：
--
作者：
Chappell, Michael A.;Woolrich, Mark W.;Payne, Stephen J.
在用于定量脑灌注的动脉自旋标记MRI方法的各种实现中，QUASAR方法是唯一的。通过结合使用带和不带血流抑制梯度的标记，QUASAR方法提供了大血管和组织信号的分离。这允许定义局部动脉输入函数，并使用数值去卷积进行“无模型”分析。然而，目前尚不清楚动脉自旋标记数据是否最好使用无模型或基于模型的分析。这项工作提供了一个关键的比较，这两种方法的QUASAR动脉自旋标记在健康的大脑。现有的两个组件（动脉和组织）模型扩展到QUASAR的混合流抑制计划，以提供最佳的基于模型的分析。扩展了基于模型的分析，以纳入标记推注的分散度，这通常被视为两种分析方法之间差异的主要来源。无模型和基于模型的分析进行了比较灌注定量，包括绝对测量，不确定性估计，脑血流估计的空间变化。无模型和基于模型的分析之间的差异的主要来源归因于分散的影响和这两种方法可以分离大血管和组织信号的程度。(C)2012 Wiley Periodicals，Inc.
Amongst the various implementations of arterial spin labeling MRI methods for quantifying cerebral perfusion, the QUASAR method is unique. By using a combination of labeling with and without flow suppression gradients, the QUASAR method offers the separation of macrovascular and tissue signals. This permits local arterial input functions to be defined and "model-free" analysis, using numerical deconvolution, to be used. However, it remains unclear whether arterial spin labeling data are best treated using model-free or model-based analysis. This work provides a critical comparison of these two approaches for QUASAR arterial spin labeling in the healthy brain. An existing two-component (arterial and tissue) model was extended to the mixed flow suppression scheme of QUASAR to provide an optimal model-based analysis. The model-based analysis was extended to incorporate dispersion of the labeled bolus, generally regarded as the major source of discrepancy between the two analysis approaches. Model-free and model-based analyses were compared for perfusion quantification including absolute measurements, uncertainty estimation, and spatial variation in cerebral blood flow estimates. Major sources of discrepancies between model-free and model-based analysis were attributed to the effects of dispersion and the degree to which the two methods can separate macrovascular and tissue signal. (C) 2012 Wiley Periodicals, Inc.