UNASSIGNED:作为手术前评估的一部分,将颅内电极植入耐药癫痫患者体内。这允许以出色的空间和时间分辨率研究正常和病理性的大脑功能。空间分辨率依赖于精确定位大脑皮层中植入电极的方法,这对于得出有关脑功能解剖定位的有效推论至关重要。已经开发了多种方法来定位电极,主要依靠植入前MRI和植入后计算机断层扫描(CT)图像。然而,它们很难验证,因为没有真实的数据来测试它们,也没有标准的方法来系统地量化它们的表现。换句话说,他们的验证缺乏标准化。我们的工作旨在模拟颅内电极阵列并模拟现实的植入场景,从而为定位算法提供评估和优化其性能的新方法。
UNASSIGNED:我们实现了新的方法来模拟植入网格的坐标,strips,和深度电极,以及这些产生的CT伪影。我们成功地模拟了现实的植入场景,包括不同的尺寸,电极间距离,和大脑区域。总的来说,在大脑表面安装了3,300个网格和条,并对穿透皮质组织的850个深度电极阵列进行了建模。在12种不同噪声水平下,在电极位置模拟了真实的CT伪影。总之,在这些情况下模拟了50,000个阈值CT伪影阵列,并用来自17名患者的关于坐标\'空间变形的真实数据进行了验证,和CT伪影的形状,强度分布,和噪音水平。最后,我们提供了一个示例,说明如何使用仿真平台来表征两种基于集群的定位方法的性能。
UNASSIGNED:我们成功开发了第一个对植入颅内网格进行建模的平台,strips,和深度电极,并逼真地模拟阈值CT伪影及其噪声。这些方法为开发更复杂的模型提供了基础,而模拟允许对电极定位技术的性能进行系统评估。本文描述的方法,以及从模拟中获得的结果,可通过开放存储库免费获得。还可以通过开源iElectrodes工具箱访问图形用户界面实现。
UNASSIGNED: Intracranial electrodes are implanted in patients with drug-resistant epilepsy as part of their pre-surgical evaluation. This allows the investigation of normal and pathological brain functions with excellent spatial and temporal resolution. The spatial resolution relies on methods that precisely localize the implanted electrodes in the cerebral cortex, which is critical for drawing valid inferences about the anatomical localization of brain function. Multiple methods have been developed to localize the electrodes, mainly relying on pre-implantation MRI and post-implantation computer tomography (CT) images. However, they are hard to validate because there is no ground truth data to test them and there is no standard approach to systematically quantify their performance. In other words, their validation lacks standardization. Our work aimed to model intracranial electrode arrays and simulate realistic implantation scenarios, thereby providing localization algorithms with new ways to evaluate and optimize their performance.
UNASSIGNED: We implemented novel methods to model the coordinates of implanted grids, strips, and depth electrodes, as well as the CT artifacts produced by these. We successfully modeled realistic implantation scenarios, including different sizes, inter-electrode distances, and brain areas. In total, ∼3,300 grids and strips were fitted over the brain surface, and ∼850 depth electrode arrays penetrating the cortical tissue were modeled. Realistic CT artifacts were simulated at the electrode locations under 12 different noise levels. Altogether, ∼50,000 thresholded CT artifact arrays were simulated in these scenarios, and validated with real data from 17 patients regarding the coordinates\' spatial deformation, and the CT artifacts\' shape, intensity distribution, and noise level. Finally, we provide an example of how the simulation platform is used to characterize the performance of two cluster-based localization methods.
UNASSIGNED: We successfully developed the first platform to model implanted intracranial grids, strips, and depth electrodes and realistically simulate thresholded CT artifacts and their noise. These methods provide a basis for developing more complex models, while simulations allow systematic evaluation of the performance of electrode localization techniques. The methods described in this article, and the results obtained from the simulations, are freely available via open repositories. A graphical user interface implementation is also accessible via the open-source iElectrodes toolbox.