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首页> 外文期刊>Journal of Cerebral Blood Flow and Metabolism: Official Journal of the International Society of Cerebral Blood Flow and Metabolism >Time delay processing of hypercapnic fMRI allows quantitative parameterization of cerebrovascular reactivity and blood flow delays
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Time delay processing of hypercapnic fMRI allows quantitative parameterization of cerebrovascular reactivity and blood flow delays

机译：高碳酸血症功能磁共振成像的延时处理可对脑血管反应性和血流延迟进行定量参数化

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摘要

Blood oxygenation level-dependent fMRI contrast depends on the volume and oxygenation of blood flowing through the circulatory system. The effects on image intensity depend temporally on the arrival of blood within a voxel, and signal can be monitored during the time course of such blood flow. It has been previously shown that the passage of global endogenous variations in blood volume and oxygenation can be tracked as blood passes through the brain by determining the strength and peak time lag of their cross-correlation with blood oxygenation level-dependent data. By manipulating blood composition using transient hypercarbia and hyperoxia, we can induce much larger oxygenation and volume changes in the blood oxygenation level-dependent signal than result from natural endogenous fluctuations. This technique was used to examine cerebrovascular parameters in healthy subjects (n=8) and subjects with intracranial stenosis (n = 22), with a subgroup of intracranial stenosis subjects scanned before and after surgical revascularization (n = 6). The halfwidth of cross-correlation lag times in the brain was larger in IC stenosis subjects (21.21 +/- 14.22s) than in healthy control subjects (8.03 +/- 3.67), p < 0.001, and was subsequently reduced in regions that co-localized with surgical revascularization. These data show that blood circulatory timing can be measured robustly and longitudinally throughout the brain using simple respiratory challenges.
机译：取决于血液氧合水平的fMRI对比取决于流经循环系统的血液的体积和氧合。对图像强度的影响在时间上取决于血液在体素内的到达，并且可以在这种血液流动的时间过程中监视信号。先前已经表明，通过确定血液与大脑氧合水平相关数据的相互关系的强度和峰值时间滞后，可以追踪随着血液流经大脑而引起的血容量和氧合整体内源性变化的通过。通过使用短暂的高碳酸血症和高氧血症来操纵血液成分，与自然内源性波动相比，我们可以在取决于血液氧合水平的信号中诱导更大的氧合和体积变化。该技术用于检查健康受试者（n = 8）和颅内狭窄受试者（n = 22）的脑血管参数，并在外科血管重建术之前和之后扫描颅内狭窄受试者的亚组（n = 6）。 IC狭窄受试者（21.21 +/- 14.22s）的大脑中互相关滞后时间的半角比健康对照受试者（8.03 +/- 3.67）的大，p <0.001，随后在相互关联的区域减小-局部与手术血运重建有关。这些数据表明，使用简单的呼吸挑战，就可以在整个大脑中可靠地纵向测量血液循环的时机。

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