>>ls brain*
brain.finalsurfs.mgz  brainmask.auto.mgz  brainmask.mgz  brain.mgz

mri_convert ./brain.mgz --in_type mgz --out_type nii -o ./brain.nii

$Id: mri_convert.c,v 1.179.2.2 2011/05/16 20:53:47 greve Exp $
reading from ./brain.mgz...
Segmentation fault (core dumped)