Any toolbox in calculating cross-correlation matrix for fMRI(.nii) data

I have a 4D fMRI data file (.nii). I was wondering how I can calculate the cross-correlation of the time-series between different voxels for the whole brain image(acquire a cross-correlation matrix in the end)? Is there any software(toolbox) at hand that I can use instead of creating my own code? I know there is one called NIFIT toolbox but I did not find very many usefulness in calculating cross-correlation. If there is not, how can I extract the time-course for all the voxels in the whole brain?