Temporal spatial differences observed by functional MRI and human intraoperative optical imaging
Temporal spatial differences observed by functional MRI and human intraoperative optical imaging
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DOI：
10.1093/cercor/11.8.773
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发表时间：
2001-08-01
期刊：
影响因子：
3.7
通讯作者：
Toga, AW
中科院分区：
文献类型：
--
作者：
Cannestra, AF;Pouratian, N;Toga, AW
术前功能性磁共振成像（fMRI）。采用皮层诱发电位（EPs）和术中内源性信号光学成像（iOIS）研究人脑感觉运动反应的时空特征。在8例接受神经外科手术的患者中，通过110 Hz手指振动器或经皮正中神经刺激提供外周躯体感觉刺激（2 s）。每种技术都提供了独特的空间模式和时间响应曲线。在中央前回和中央后回（上级回水平）的表面上观察到EP和iOIS活动，具有非常相似的空间分布。相反，功能磁共振成像的空间分布依赖于用于统计相关性分析的模型。使用双相反应模型，功能磁共振成像主要定位在中央沟内，并没有表现出大的信号变化，在前和后中央回（与iOIS/EP活动的地区）。然而，随着最初的负反应被纳入反应模型，功能磁共振成像逐渐定位更接近iOIS和体感EP地图。在时间上，对单一刺激的反应在fMRI和iOIS技术之间不同。使用双相模型进行fMRI分析，总的fMRI反应相对于iOIS延迟2 - 3 s。由于最初的负面反应被纳入分析，功能磁共振成像的时间过程开发的时间特性类似于iOIS。最后，当在与iOIS激活共定位的像素上检查fMRI时间过程时（不使用统计相关性分析），fMRI时间曲线包括与iOIS响应的时间过程非常相似的信号的初始降低（初始下降）。这是第一项研究，实验cc本地化（时间和空间）的iOIS和功能磁共振成像信号在人类受试者。本研究中的空间/时间差异可能分别反映了iOIS和fMRI的毛细血管与静脉贡献。iOIS信号和fMRI初始下降的时间/空间cc定位表明，初始fMRI下降和iOIS信号可能由相似的生理事件引起。
Pre-operative functional magnetic resonance imaging (fMRI). cortical evoked potentials (EPs) and intraoperative optical imaging of intrinsic signals (iOIS) were employed to relate the temporal-spatial characteristics of sensorimotor responses in human brain. Peripheral somasthetic stimulation (2 s) was provided either by a 110 Hz finger vibrator or transcutaneous median nerve stimulation in eight patients undergoing neurosurgical procedures. Each technique provided unique spatial patterns and temporal response profiles. EPs and iOIS activities were observed over the surface of pre- and post-central gyri (at the level of the superior genu) with very similar spatial distributions. In contrast, fMRI spatial distributions depended upon the model used for statistical correlation analysis. Using a monophasic response model, fMRI primarily localized within the central sulcus and did not demonstrate large signal changes over the pre- and post-central gyri (areas with iOIS/EP activity). However, as initial negative responses were incorporated into the response model, fMRI progressively localized closer to the iOIS and somatosensory EP maps. Temporally, responses to single stimuli differed between the fMRI and iOIS techniques. Using a monophasic model for fMRI analysis, the total fMRI response was delayed by 2-3 s relative to iOIS. As initial negative responses were incorporated in the analysis, the fMRI time course developed temporal characteristics similar to iOIS. Ultimately, when fMRI time courses were examined over pixels co-localizing with iOIS activation (without using statistical correlation analysis), the fMRI temporal profile included an initial decrease in signal (an initial dip) that closely resembled the time course of iOIS response. This is the first study to experimentally cc-localize (temporally and spatially) iOIS and fMRI signals in human subjects. The spatial/temporal differences in this study likely reflect the capillary versus venous contributions of iOIS and fMRI, respectively. The temporal/spatial cc-localization of the iOIS signal and the fMRI initial dip suggests the initial fMRI dip and the iOIS signal may result from similar physiologic events.