MRIcro is a free medical image viewer for Windows. It can display and convert Analyze, DICOM, ECAT, NEMA, GE Signa & LX, Interfile, Picker CT, Siemens Magnetom, and raw data format images.
A tutorial (with sample MRI and MRI info) is also available:
NMR
Information Server
http://spincore.com/nmrinfo/