"nilearn" - Augmenting Two Parcellations in a Single Masker

Hello,

I have applied Schaefer et al. (200-scale) 2018 and Tian et al. 2020 (S2 - subcortical regions downloaded from GitHub - yetianmed/subcortex) on my resting-state fMRI data, thereby extracting 273 cortico-subcortical regions. However, I did so by generating two different maskers (i.e., one per parcellation). I was wondering if there is a functionality available through nilearn that would allow me to augment these parcellations and generate a single masker that can be applied to my data.

Thank you very much for your time and kind assistance and looking forward to hearing from you.

Best,
Soheil