Multiplying TDI with relative ROI

Hi y’all,

I am fairly new to mrtrix and am currently trying to find a way to multiply a track density image to a ROI in order to retrieve the connectivity density-weighted parcels on the ROI’s volume. Both images are fixed to voxel sizes of 1 mm^3. I was thinking I could use the mrcalc function, but the documentation does not seem to mention that this could be done.

Thank you for your help!