Department of Biomedical Engineering, Linköping University, Linköping, Sweden.
Med Biol Eng Comput. 2012 Jan;50(1):23-32. doi: 10.1007/s11517-011-0842-z. Epub 2011 Nov 19.
The aim was to quantify the influence of heterogeneous isotropic and heterogeneous anisotropic tissue on the spatial distribution of the electric field during deep brain stimulation (DBS). Three finite element tissue models were created of one patient treated with DBS. Tissue conductivity was modelled as (I) homogeneous isotropic, (II) heterogeneous isotropic based on MRI, and (III) heterogeneous anisotropic based on diffusion tensor MRI. Modelled DBS electrodes were positioned in the subthalamic area, the pallidum, and the internal capsule in each tissue model. Electric fields generated during DBS were simulated for each model and target-combination and visualized with isolevels at 0.20 (inner), and 0.05 V mm(-1) (outer). Statistical and vector analysis was used for evaluation of the distribution of the electric field. Heterogeneous isotropic tissue altered the spatial distribution of the electric field by up to 4% at inner, and up to 10% at outer isolevel. Heterogeneous anisotropic tissue influenced the distribution of the electric field by up to 18 and 15% at each isolevel, respectively. The influence of heterogeneous and anisotropic tissue on the electric field may be clinically relevant in anatomic regions that are functionally subdivided and surrounded by multiple fibres of passage.
目的是量化在深部脑刺激 (DBS) 过程中，各向同性和各向异性组织的不均匀性对电场空间分布的影响。为一位接受 DBS 治疗的患者创建了三个有限元组织模型。组织电导率被建模为 (I) 各向同性均匀、(II) 基于 MRI 的各向异性不均匀、和 (III) 基于弥散张量 MRI 的各向异性不均匀。在每个组织模型中，将模拟的 DBS 电极放置在丘脑下核区、苍白球和内囊。针对每个模型和靶点组合，模拟了 DBS 期间产生的电场，并以 0.20（内部）和 0.05 V mm(-1)（外部）的等位面可视化电场分布。统计和向量分析用于评估电场的分布。各向同性不均匀组织在内部等位面处改变了电场的空间分布，最大可达 4%，在外部等位面处最大可达 10%。各向异性不均匀组织分别在每个等位面处对电场分布的影响可达 18%和 15%。在功能上细分并被多个穿行纤维包围的解剖区域，不均匀和各向异性组织对电场的影响可能具有临床相关性。
