Clinical Brain Disorders Branch, NIMH, NIH, Washington, District of Columbia 20032, USA.
Hum Brain Mapp. 1996;4(2):113-21. doi: 10.1002/(SICI)1097-0193(1996)4:2<113::AID-HBM3>3.0.CO;2-6.
This study is an investigation into the reproducibility of brain activation in the sensorimotor cortex obtained with 3D "PRESTO" fMRI on eleven normal subjects. During one session, two series of functional scans were acquired while the subjects performed a finger opposition task (2 Hz). Nine subjects were tested once more on a different day. Each individual motor trial was analyzed separately, with a conservative zt-based method. Using these results, the agreement between repeated series was examined in a number of ways, comparing the two series within one session, and the two series across sessions. In 28 of the 31 series (90%) significant signal change was found in the contralateral primary sensorimotor cortex (PSM). Overall, 0.20% of all voxels (total about 11,000) in the scanned volume reached significance, and approximately 60% of the significant positive signal changes were located in the PSM (P<5x10(-7) for a chance occurrence). Comparisons within and across sessions yielded similar results: there was a 20-30% overlap of the clusters of activated voxels in the PSM (chance overlap within the PSM: P<0.01). The mean distance between zt-weighted centers of mass was 4.0-4.4 mm (chance distance within the PSM: P=0.033 and 0.058, respectively). No significant difference was found between series in the magnitude of significant signal change. Whereas the number of activated voxels in the PSM was not consistently correlated between series, the ratio of this number over the total number of activated voxels in the scanned volume was significantly correlated (rho=0.75-0.79, P<0.05). These results indicate that activation in sensorimotor cortex associated with oppositional finger movement is reliably mapped with 3D PRESTO fMRI.
本研究旨在调查在 11 名正常受试者中使用 3D“PRESTO”fMRI 获得的感觉运动皮层脑激活的可重复性。在一次实验中，当受试者执行手指对指任务（2Hz）时，采集了两个系列的功能扫描。其中 9 名受试者在不同的日子再次接受了测试。每个个体运动试验分别进行分析，采用保守的基于 zt 的方法。使用这些结果，以多种方式检查了重复系列之间的一致性，即在一次实验中比较两个系列，以及在两次实验中比较两个系列。在 31 个系列中的 28 个（90%）中，在对侧初级感觉运动皮层（PSM）中发现了显著的信号变化。总的来说，扫描体积中所有体素的 0.20%（总计约 11000 个）达到了显著水平，大约 60%的显著正信号变化位于 PSM 中（发生机会为 5x10(-7) 的情况下为 P<5x10(-7)）。在实验内和实验间的比较得出了相似的结果：PSM 中激活体素的簇有 20-30%的重叠（PSM 内的机会重叠：P<0.01）。zt 加权质心之间的平均距离为 4.0-4.4mm（PSM 内的机会距离：P=0.033 和 0.058）。在两个系列之间，显著信号变化的幅度没有发现显著差异。虽然 PSM 中激活体素的数量在两个系列之间没有一致的相关性，但这个数量与扫描体积中激活体素总数的比值与显著相关（rho=0.75-0.79，P<0.05）。这些结果表明，使用 3D PRESTO fMRI 可以可靠地绘制与对指运动相关的感觉运动皮层的激活图。
