Download MIPAV: http://mipav.cit.nih.gov  After you open your image, select Utilities->4D Volume tools->Remove volumes. Check time points 0-9.  Your final result image is the one you want.

To make it callable from the command line, open Scripts->Record Script before you run the above.  After saving your script it would be called using ./mipav -s myScript.sct -i myImage.nii

This can now be run in an automated pipeline, or you can also integrate it into a JIST pipeline: http://www.nitrc.org/projects/jist