Simultaneous recording of task-induced changes in blood oxygenation, volume, and flow using diffuse optical imaging and arterial spin-labeling MRI
Simultaneous recording of task-induced changes in blood oxygenation, volume, and flow using diffuse optical imaging and arterial spin-labeling MRI
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DOI：
10.1016/j.neuroimage.2004.12.032
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发表时间：
2005-04-15
期刊：
影响因子：
5.7
通讯作者：
Boas, DA
中科院分区：
文献类型：
--
作者：
Hoge, RD;Franceschini, MA;Boas, DA
脑组织中神经活动的增加伴随着一系列支持的生理过程，包括血流量的增加以及葡萄糖和氧气的消耗速度。这些反应导致二次效应，如血氧和血容量的变化，并最终决定血氧水平依赖(BOLD)信号的幅度和时间特征，普遍用于绘制大脑功能图。我们使用光学和基于MRI的成像方法相结合的方法进行了实验，以开发更全面的图像，以了解在手指对位任务中伴随初级运动皮质激活的生理事件。组织血红蛋白浓度变化的时间分布与基于MRI的血流和氧合信号的观察结果定性相似。定量分析显示HBO、HBr、总Hb、脑血流和BOLD MRI信号的峰值变化分别为+16+/-2%、-132%、+8+/-3%、+83+/-9%和+1.4+/-0.1%。质量平衡模型被用来估计光学和流动测量所隐含的氧化代谢速率的变化，导致计算值为+47+/-5%。应该注意的是，光学和MRI观察通常可以反映不同体积的组织的变化。氧化代谢的部分变化与血流的部分变化的比率被发现为0.56+/-0.08，与以前关于流动-代谢耦合的研究基本一致。(C)2004年，爱思唯尔公司出版。
Increased neural activity in brain tissue is accompanied by an array of supporting physiological processes, including increases in blood flow and the rates at which glucose and oxygen are consumed. These responses lead to secondary effects such as alterations in blood oxygenation and blood volume, and are ultimately the primary determinants of the amplitude and temporal signature of the blood oxygenation level-dependent (BOLD) signal used prevalently to map brain function. We have performed experiments using a combination of optical and MRI-based imaging methods to develop a more comprehensive picture of the physiological events accompanying activation of primary motor cortex during a finger apposition task. Temporal profiles for changes in tissue hemoglobin concentrations were qualitatively similar to those observed for MRI-based flow and oxygenation signals. Quantitative analysis of these signals revealed peak changes of +16 +/- 2% for HbO, - 13 2% for HbR, +8 +/- 3% for total Hb, +83 +/- 9% for cerebral blood flow, and +1.4 +/- 0.1% for the BOLD MRI signal. A mass balance model was used to estimate the change in rate of oxidative metabolism implied by the optical and flow measurements, leading to a computed value of +47 +/- 5%. It should be noted that the optical and MRI observations may in general reflect changes over different volumes of tissue. The ratio of fractional changes in oxidative metabolism to fractional change in blood flow was found to be 0.56 +/- 0.08, in general agreement with previous studies of flow-metabolism coupling. (c) 2004 Published by Elsevier Inc.