Comparison of functional connectivity in default mode and sensorimotor networks at 3 and 7T
Comparison of functional connectivity in default mode and sensorimotor networks at 3 and 7T
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DOI：
10.1007/s10334-010-0220-0
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发表时间：
2010-12-01
影响因子：
2.3
通讯作者：
Morris, Peter G.
中科院分区：
文献类型：
--
作者：
Hale, Joanne R.;Brookes, Matthew J.;Morris, Peter G.
本研究的目的是评估在超高场(7T)下的功能连通性测量，与噪声比随磁场强度增大而增大形成鲜明对比，但生理噪声也随之增加。在3和7T时采集最新状态BOLD数据以评估不同空间平滑水平下感觉运动网络(SMN)和默认模式网络(DMN)中的连通性。在3和7T时观察到右侧感觉运动种子和左侧感觉运动皮质之间的正相关。对于DMN，后扣带回皮质的种子导致下顶叶和内侧前额叶高度相关。在所有平滑程度下，7T下SMN和DMN的时间相关系数均高于3T。连通性地图之间的空间相关性表明SMN没有显著差异，而DMN显示出依赖于SNR的空间相关性增加。生理校正后MAP图的空间相关性无显著差异，7T时最大生理噪声贡献率较高，但种子节点和网络节点的噪声没有显著增加。7T可以提高连通性地图的空间特异性，便于在内在网络相关性较低的区域测量连通性。
The objective of this work was to assess functional connectivity measurements at ultra-high field (7T), given BOLD contrast to noise ratio increases with magnetic field strength but physiological noise also increases.Resting state BOLD data were acquired at 3 and 7T to assess connectivity in the sensorimotor network (SMN) and default mode network (DMN) at different spatial smoothing levels.At 3 and 7T positive correlation is observed between a right sensorimotor seed and left sensorimotor cortex. For the DMN, a seed in posterior cingulate cortex results in a high correlation in inferior parietal lobes and medial prefrontal cortex. We show higher temporal correlation coefficients for both the SMN and DMN at 7T compared to 3T for all smoothing levels. A spatial correlation between connectivity maps revealed no significant differences for the SMN, whilst the DMN showed increased spatial correlation dependent on SNR. The maximum physiological noise contribution was found to be higher at 7T, but noise in both seed and network nodes was not significantly increased, as shown by no significant difference in the spatial correlation of maps following physiological correction.7T can improve spatial specificity of connectivity maps and facilitate measurement of connectivity in areas of lower intrinsic network correlation.