Changing head model extent affects finite element predictions of transcranial direct current stimulation distributions.
Changing head model extent affects finite element predictions of transcranial direct current stimulation distributions.
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DOI：
10.1088/1741-2560/13/6/066006
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发表时间：
2016-12
影响因子：
4
通讯作者：
Sadleir RJ
中科院分区：
文献类型：
--
作者：
Indahlastari A;Chauhan M;Schwartz B;Sadleir RJ
在这项研究中，我们确定了相对于经颅直流电刺激（tDCS）预测电流密度的有效头部模型尺寸。效率指标的定义是基于基于单一MRI数据集的9个人体头部模型进行的有限元（FE）模拟，其范围从原始轴向范围的60-100%不等。模型采用各向异性白质等11种组织类型和T7-T8、f3 -右眶上、Cz-Oz三种电极蒙太奇。将头部体积范围从100%减少到60%，即将模型的轴向范围从顶点和C3椎体之间改变为仅包括顶点到上小脑的轴向范围，可将总建模时间减少多达一半。每个模型中电流密度预测之间的差异通过使用相对差异测量（RDM）进行量化。我们的模拟结果表明，对于从颅骨顶点到颅骨底部（60-75%的体积）建模的头部体积，RDM受影响最小（最大误差为10%）。这一发现表明，骨可以作为生物电边界，因此，在大多数情况下，为了获得电流密度结果的合理精度，不需要在人类头部上进行tDCS的有限元模拟，模型延伸到下颅骨之外。
In this study, we determined efficient head model sizes relative to predicted current densities in transcranial direct current stimulation (tDCS). Efficiency measures were defined based on a finite element (FE) simulations performed using nine human head models derived from a single MRI data set, having extents varying from 60-100% of the original axial range. Eleven tissue types, including anisotropic white matter, and three electrode montages (T7-T8, F3-right supraorbital, Cz-Oz) were used in the models. Reducing head volume extent from 100% to 60%, that is, varying the model’s axial range from between the apex and C3 vertebra to one encompassing only apex to the superior cerebellum, was found to decrease the total modeling time by up to half. Differences between current density predictions in each model were quantified by using a relative difference measure (RDM). Our simulation results showed that RDM was the least affected (a maximum of 10% error) for head volumes modeled from the apex to the base of the skull (60-75% volume). This finding suggested that the bone could act as a bioelectricity boundary and thus performing FE simulations of tDCS on the human head with models extending beyond the inferior skull may not be necessary in most cases to obtain reasonable precision in current density results.