Hello,

What is the best way you would recommend to merge the overlay maps onto one side of the brain? For example to have all lesions appear on the right hemisphere? 
Many thanks in advance for your help.

Sincerely,
Manuel

This is a perfect job for a small Matlab or Python script. For Matlab, use fliplr. For Python, use fliplr. Be aware that the brain is asymmetric, with most individuals showing Yakovlevian torque. Many (though not all) normalization templates represent this asymmetry. Therefore, you might want to flip all lesions to the same hemisphere prior to normalization.