I just wanted to give people some warning about unpacking/converting anonymized Siemens dicom files. Siemens inserts some ascii information into their dicom files (what I call the "ascii header"). This is inserted into a "private" field in the dicom header. Some anonymizers will strip this information out of the dicom file.
If the dicom file contains a mosiac (eg, as with functionals), then it will not be possible to unpack it using the tools in freesurfer if the ascii header is gone.
If the dicom file contains individual slice images (non-mosaics), then it is possible to unpack it correctly even if their is no ascii header. There is currently a bug in mri_convert/unpacksdcmdir that might cause a slice reversal if the ascii header is not there. If you acquired data sagitally, this would mean a left-right flip.
This bug has been fixed (live in dev and stable tomorrow). Even so, be very careful when anonymizing your data. You should do some sort of check against unanonymized data to assure that nothing funny has happened.
doug