Qiu Tianming, Hameed N U Farrukh, Lin Ching-Po, Biswal Bharat B, Wu Jinsong
Department of Neurosurgery, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
Neurosurgical Institute of Fudan University, Shanghai, China.
Front Hum Neurosci. 2020 Oct 2;14:569463. doi: 10.3389/fnhum.2020.569463. eCollection 2020.
FMRI signal amplitude can change during stimulus presentation due to underlying neural function and hemodynamic responses limiting the accuracy of fMRI in pre-surgical planning. To account for these changes in fMRI activation signal, we used breath-hold tasks to mimic hemodynamic changes in brain tumor subjects and scaled the activation response. Motor and/or language fMRI was performed in 21 subjects with brain tumor. A breath-hold task was also performed in these subjects to obtain the hemodynamic response changes independent of neural changes. The task activation signals were calibrated on a voxel wise basis for all the subjects. Direct cortical stimulation was used to verify the scaled results of task-based fMRI. After scaling for the hemodynamic response function (HRF) on a voxel wise basis, the spatial extent of the scaled activation was more clustered together and appeared to minimize false positives. Similarly, accounting for the underlying canonical HRF, the percentage increase of active voxels after scaling had lower standard non-deviation suggesting that the activation response across voxels were more similar. Although preliminary in nature, this study suggests that the variation in hemodynamic changes can be calibrated using breath-hold in brain tumor subjects and can also be used for other clinical cases where the underlying HRF has been altered.
由于潜在的神经功能和血液动力学反应，功能磁共振成像（fMRI）信号幅度在刺激呈现期间可能会发生变化，这限制了fMRI在术前规划中的准确性。为了考虑fMRI激活信号中的这些变化，我们使用屏气任务来模拟脑肿瘤患者的血液动力学变化并对激活反应进行缩放。对21名脑肿瘤患者进行了运动和/或语言功能磁共振成像检查。还对这些患者进行了屏气任务，以获得独立于神经变化的血液动力学反应变化。对所有患者的任务激活信号在体素水平上进行校准。使用直接皮层刺激来验证基于任务的功能磁共振成像的缩放结果。在体素水平上对血液动力学反应函数（HRF）进行缩放后，缩放激活的空间范围更聚集在一起，似乎将假阳性最小化。同样，考虑到潜在的典型HRF，缩放后活跃体素的百分比增加具有较低的标准偏差，表明跨体素的激活反应更相似。尽管本质上是初步的，但这项研究表明，血液动力学变化的差异可以通过脑肿瘤患者的屏气进行校准，也可用于其他潜在HRF已改变的临床病例。
