Transcranial magnetic stimulation (TMS) is a noninvasive method to stimulate the cerebral cortex that has applications in psychiatry, such as in the treatment of depression and anxiety. Although many TMS targeting methods that use figure-8 coils exist, many do not account for individual differences in anatomy or are not generalizable across target sites. This protocol combines functional magnetic resonance imaging (fMRI) and iterative electric-field (E-field) modeling in a generalized approach to subject-specific TMS targeting that is capable of optimizing the stimulation site and TMS coil orientation. To apply this protocol, the user should (i) operationally define a region of interest (ROI), (ii) generate the head model from the structural MRI data, (iii) preprocess the functional MRI data, (iv) identify the single-subject stimulation site within the ROI, and (iv) conduct E-field modeling to identify the optimal coil orientation. In comparison with standard targeting methods, this approach demonstrates (i) reduced variability in the stimulation site across subjects, (ii) reduced scalp-to-cortical-target distance, and (iii) reduced variability in optimal coil orientation. Execution of this protocol requires intermediate-level skills in structural and functional MRI processing. This protocol takes ~24 h to complete and demonstrates how constrained fMRI targeting combined with iterative E-field modeling can be used as a general method to optimize both the TMS coil site and its orientation.

经颅磁刺激 (TMS) 是一种刺激大脑皮层的无创方法，可用于精神病学，例如治疗抑郁症和焦虑症。尽管存在许多使用 8 字形线圈的 TMS 靶向方法，但许多方法没有考虑解剖结构中的个体差异，或者不能在目标部位之间推广。该协议将功能磁共振成像 (fMRI) 和迭代电场 (E-field) 建模结合到特定主题 TMS 靶向的通用方法中，能够优化刺激部位和 TMS 线圈方向。要应用此协议，用户应 (i) 在操作上定义感兴趣区域 (ROI)，(ii) 从结构 MRI 数据生成头部模型，(iii) 预处理功能 MRI 数据，(iv) 识别单- ROI 内的受试者刺激部位，以及 (iv) 进行电场建模以确定最佳线圈方向。与标准靶向方法相比，该方法证明（i）减少了受试者刺激部位的变异性，（ii）减少了头皮到皮质目标距离，以及（iii）减少了最佳线圈方向的变异性。该协议的执行需要结构和功能 MRI 处理方面的中级技能。该协议需要约 24 小时才能完成，并演示了如何将约束 fMRI 靶向与迭代电场建模相结合用作优化 TMS 线圈位置及其方向的通用方法。