MIPAV (Medical Image Processing, Analysis, and Visualization) is a software for viewing medical images.
Download MIPAV here: http://mipav.cit.nih.gov
Some video tutorials for MIPAV: https://www.youtube.com/user/MIPAVvideos
You can use JIST (Java Image Science Toolkit) to do image processing for strutucural MRI through MIPAV
