If I have four regressors at the group level ( and each has con and t maps), I would like a way of selecting the highest T-values for each voxel. 

For example: 

If A gives me a t value of 5 in -34 60 10 

and B gives me a t value of 4 in the same coordinate, then I want away of returning only a map contains the B result AND telling me that this B. 

Can I do this with ImCalc or peak nii, your help is appreciated 

Thanks

Aser