Vanderbilt University Institute of Imaging Science, Nashville, TN, USA.
PLoS One. 2009 Aug 17;4(8):e6660. doi: 10.1371/journal.pone.0006660.
The capabilities of magnetic resonance imaging (MRI) to measure structural and functional connectivity in the human brain have motivated growing interest in characterizing the relationship between these measures in the distributed neural networks of the brain. In this study, we attempted an integration of structural and functional analyses of the human language circuits, including Wernicke's (WA), Broca's (BA) and supplementary motor area (SMA), using a combination of blood oxygen level dependent (BOLD) and diffusion tensor MRI.
METHODOLOGY/PRINCIPAL FINDINGS: Functional connectivity was measured by low frequency inter-regional correlations of BOLD MRI signals acquired in a resting steady-state, and structural connectivity was measured by using adaptive fiber tracking with diffusion tensor MRI data. The results showed that different language pathways exhibited different structural and functional connectivity, indicating varying levels of inter-dependence in processing across regions. Along the path between BA and SMA, the fibers tracked generally formed a single bundle and the mean radius of the bundle was positively correlated with functional connectivity. However, fractional anisotropy was found not to be correlated with functional connectivity along paths connecting either BA and SMA or BA and WA.
CONCLUSIONS/SIGNIFICANCE: These findings suggest that structure-function relations in the human language circuits may involve a number of confounding factors that need to be addressed. Nevertheless, the insights gained from this work offers a useful guidance for continued studies that may provide a non-invasive means to evaluate brain network integrity in vivo for use in diagnosing and determining disease progression and recovery.
磁共振成像（MRI）在测量人脑结构和功能连接方面的能力，激发了人们对描述大脑分布式神经网络中这些测量值之间关系的浓厚兴趣。在这项研究中，我们尝试整合人类语言回路的结构和功能分析，包括韦尼克区（WA）、布罗卡区（BA）和补充运动区（SMA），使用血氧水平依赖（BOLD）和弥散张量 MRI 的组合。
方法/主要发现：功能连接通过在静息稳态下采集的 BOLD MRI 信号的低频区域间相关性来测量，结构连接通过使用扩散张量 MRI 数据进行自适应纤维跟踪来测量。结果表明，不同的语言通路表现出不同的结构和功能连接，表明不同区域之间的处理存在不同程度的相互依赖。在 BA 和 SMA 之间的路径上，跟踪的纤维通常形成单个束，束的平均半径与功能连接呈正相关。然而，发现各向异性分数与 BA 和 SMA 或 BA 和 WA 之间连接路径的功能连接不相关。
结论/意义：这些发现表明，人类语言回路的结构-功能关系可能涉及到一些需要解决的混杂因素。尽管如此，这项工作的见解为进一步的研究提供了有益的指导，可能提供一种非侵入性的方法来评估体内大脑网络的完整性，用于诊断、确定疾病进展和恢复。
