Hi,
Thanks so much for the quick response.
When I ran the 3dinfo, it gave me the following output
$ 3dinfo -n4 LME_3Grp_covar_resid.nii.gz
121 145 121 198
Regarding of the second issue you pointed out, these are not functional data. They are structural data so resolutions appeared to be higher with 1.5mmx3.