Fig. 1. Schematic representation of modelling pipeline.
A Each patient’s T1-weighted brain scan was preprocessed to interpolate a 1 mm isotropic standard MPRAGE research scan from a clinical scan. B The preprocessed T1 was segmented to create a 3D head model. Coil center coordinates were determined by transforming MNI coordinates of M1 into each patient’s native space, and assuming that stimulation was applied 50 mm anterior to M1. C A computational model of the H1 coil was used for electric (E-)field simulation at the identified target location. D The magnitude of the simulated E-field volume of each patient was thresholded to extract the strongest E-field. This was used as seed for seed-based functional connectivity analyses: across 1000 subjects from a normative connectome, the Fisher-z transformed Pearson correlation was computed between the seed and every other voxel in the brain. For each patient, an average map was created across the 1000 subjects. Spearman’s correlation was used to correlate clinical outcome with thresholded and unthresholded E-field magnitude volumes, and average normative E-field connectivity maps (shaded green areas across C and D). magnE: magnitude of electric field; MNI: Montreal Neurological Institute.