Examining the regional and cerebral depth-dependent BOLD cerebrovascular reactivity response at 7 T
Examining the regional and cerebral depth-dependent BOLD cerebrovascular reactivity response at 7 T
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DOI：
10.1016/j.neuroimage.2015.04.014
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发表时间：
2015-07-01
期刊：
影响因子：
5.7
通讯作者：
Hoogduin, Hans
中科院分区：
文献类型：
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作者：
Bhogal, Alex A.;Philippens, Marielle E. P.;Hoogduin, Hans
脑血流量（CBF）对高碳酸血症引起的血管张力变化的反应，即脑血管反应性（CVR），可以通过血氧水平依赖（BOLD） MR对比来测量。我们研究了BOLD- cvr对逐渐增加的高碳酸血症刺激的反应的区域差异，以及恢复基线正常碳酸血症的区域BOLD特征。9名受试者的CVR在脑叶和深部灰质中最高。这些地区的CVR峰值比基线潮末CO2高3.6 +/- 1.6 mm Hg。与灰质相比，白质CVR普遍降低（白质CVR峰值降低48%）。实测CVR峰值时的尾潮CO2值与白质深度呈正相关。此外，停止高碳酸刺激后，BOLD信号恢复到基线所需的时间也与白质深度有关；以时间常数表示的回报，相当于在白质中延长了25%。为了解释观察到的区域CVR反应差异，提出了一个考虑脑血管局部结构的模型，该模型可能导致区域血流分布随潮末CO2的变化而变化。(C) 2015爱思唯尔公司版权所有。
Changes in cerebral blood flow (CBF) in response to hypercapnia induced changes in vascular tone, known as cerebrovascular reactivity (CVR), can be measured using the Blood Oxygenation Level Dependent (BOLD) MR contrast. We examine regional differences in the BOLD-CVR response to a progressively increasing hypercapnic stimulus as well as regional BOLD characteristics for the return to baseline normocapnia. CVR across 9 subjects was highest in the cerebral lobes and deep gray matter. Peak CVR in these regions was measured at 3.6 +/- 1.6 mm Hg above baseline end-tidal CO2. White matter CVR was generally reduced compared to that of the gray matter (peak white matter CVR was similar to 48% lower). A positive relationship between the end-tidal CO2 value at which peak CVR was measured and white matter depth is observed. Furthermore, the time required for the BOLD signal to return to baseline after cessation of the hypercapnic stimulus, was also related to white matter depth; the return, expressed as a time constant, was similar to 25% longer in white matter. To explain the observed differences in regional CVR response, a model is proposed that takes into account the local architecture of the cerebrovascular, which can result in changes in regional blood flow distribution as a function of end-tidal CO2. (C) 2015 Elsevier Inc. All rights reserved.