masking corpus callosum in the stc plot

Hello,
I’m interested to see the activations in the ROIs lying in the medial view, however, I could also see some activations in the corpus callosal regions. Is it meaningful or is there any standard way (option in MNE) to mask the regions of corpus callosum when plotting the medial view? For clarity purposes, I am attaching an image where-in on the top panel is the actual image vs. on the bottom panel is the image that I intended to get.

MNE version: 1.4.2
operating system: Linux mint 19.3

Thanks in advance,
Harish