Hi Mark,

Thanks and sorry for the confusion. 

I am using a mask for my region of interest. And my question was about multiplying this mask by the sienax grey matter mask in order to have better alignment of my mask (ROI) and also to avoid having my mask encroach onto the white matter since my aim is to assess the connectivity. 

So, I was actually wondering if this step is necessary?

But now I have problems with the mask itself since it's not well aligned to my region of interest. Since this is not a manual mask, I am not able to change anything. Do you have any suggestions regarding this problem?

And regarding multiplication of mask with the sienax pve_1 grey matter, do you recommend it? 

I hope I did not cause more confusion. Thanks.