I am working with images from a Siemens 3T Trio that are interleaved.  Online I have read that the MRIcron dcm2nii can slice time correct Siemens fMRI data.  Is this what the nifti 3d-->4d option is doing?
 
thanks

My software should convert DICOM images to NIfTI regardless of slice order. However, my software saves the raw data as acquired by the scanner. You will want to use your favorite tool (SPM, FSL, AFNI) to manipulate the images if slice timing is a concern. 
  http://www.mccauslandcenter.sc.edu/crnl/tools/stc