Calculate the mean of 4D image using a 3D mask

Hi there,

I have 4D data with dimensions [308,384,26,31]=[x,y,z,time]. I also have a binary 3D mask with dimensions [308, 384, 26].

I would like to calculate the mean of my 4D data using the mask. I want basically to calculate the mean only of the regions where the mask is 1. I need to loop over the time points to calculate the mean of all the nonzero areas.

Can anyone help with that?

[Cyrus Tirband]

I tried to comment on your other question, but the website crashes when I try to. I'll respond to what you asked here in this question instead.

Guillaume's answer will give a lower mean value if 'volume' is zero in locations where the mask is not. If you want to take these points into account, I suggest using Guillaume's answer.