Investigation of BOLD fMRI resonance frequency shifts and quantitative susceptibility changes at 7 T.
Investigation of BOLD fMRI resonance frequency shifts and quantitative susceptibility changes at 7 T.
复制标题
DOI：
10.1002/hbm.22320
复制
发表时间：
2014-05
影响因子：
4.8
通讯作者：
Duyn, Jeff H.
中科院分区：
文献类型：
--
作者：
Bianciardi, Marta;van Gelderen, Peter;Duyn, Jeff H.
关键词：
虽然脑活动的血氧水平依赖（BOLD）功能磁共振成像（fMRI）实验通常依赖于信号的大小，但它们也提供了可以从信号的相位导出的频率信息。然而，由于仪器和生理来源的混杂影响，BOLD相关的频率信息很难提取，因此很少使用。在这里，我们探索了使用高场（7t）和专用信号处理方法来提取频率信息，并使用它来量化和解释血氧和血容量变化。我们发现，优化的预处理提高了对任务诱发和自发变化的相位信号和共振频率漂移的检测，其灵敏度与幅度信号相当。此外，我们的研究结果表明，绘制至少部分活化区及其最大排水静脉的BOLD定量敏感性变化是可行的。与量级数据的比较表明，观察到的敏感性变化源于神经元活动，通过诱导脑脊液和皮质内静脉的血容量和氧合变化。此外，根据频移和敏感性值，我们估计，相对于基线，刺激期间大血管的氧饱和度分数增加了0.02-0.05，这与之前发表的估计一致。综上所述，这些发现表明，从BOLD频移和定量敏感性变化的fMRI成像中可以获得有价值的信息。
Although blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI) experiments of brain activity generally rely on the magnitude of the signal, they also provide frequency information that can be derived from the phase of the signal. However, because of confounding effects of instrumental and physiological origin, BOLD related frequency information is difficult to extract and therefore rarely used. Here, we explored the use of high field (7 T) and dedicated signal processing methods to extract frequency information and use it to quantify and interpret blood oxygenation and blood volume changes. We found that optimized preprocessing improves detection of task-evoked and spontaneous changes in phase signals and resonance frequency shifts over large areas of the cortex with sensitivity comparable to that of magnitude signals. Moreover, our results suggest the feasibility of mapping BOLD quantitative susceptibility changes in at least part of the activated area and its largest draining veins. Comparison with magnitude data suggests that the observed susceptibility changes originate from neuronal activity through induced blood volume and oxygenation changes in pial and intracortical veins. Further, from frequency shifts and susceptibility values, we estimated that, relative to baseline, the fractional oxygen saturation in large vessels increased by 0.02–0.05 during stimulation, which is consistent to previously published estimates. Together, these findings demonstrate that valuable information can be derived from fMRI imaging of BOLD frequency shifts and quantitative susceptibility changes.
登录
查看更多内容
影响因子：
2.5
作者：
Bianciardi, Marta;Fukunaga, Masaki;van Gelderen, Peter;Horovitz, Silvina G.;de Zwart, Jacco A.;Shmueli, Karin;Duyn, Jeff H.
通讯作者：
Duyn, Jeff H.
影响因子：
3.3
作者：
Lee, Jongho;Shahram, Morteza;Pauly, John M.
通讯作者：
Pauly, John M.
影响因子：
5.7
作者：
Nencka, Andrew S.;Rowe, Daniel B.
通讯作者：
Rowe, Daniel B.
影响因子：
2.5
作者：
Petridou, Natalia;Schaefer, Andreas;Bowtell, Richard
通讯作者：
Bowtell, Richard
影响因子：
5.7
作者：
Rowe, DB;Logan, BR
通讯作者：
Logan, BR