Hi freesurfers,

I'm currently re-processing with FS5.1 some data that i had already processed with FS5.0 and am experiencing some unexpected issues with the linear talairach transform.

- While manually checking with Tkregister, I noticed that some off the subjects had quite unsatisfying transforms , while no talairach failure was detected on the log - The transforms looked ok for those subjects in FS 5.0 - I re-run autorecon1 using the -use-mritotal flag - While still no error in the log file, the transforms usually then look acceptable in Tkregister but completely wrong when talairach.xfm is loaded in tkmedit : transformation in the top or bottom left corners, coronal and transversal views interverted, sagittal views rotated by 90 degrees... This happens for a few (not all) of the subjects that I've re-processed with FS5.1 so far.

I'm probably doing something wrong but can't figure out what nor what to do about it. Any advice would be highly appreciated.

Thanks in advance

Myriam Siefert, MD, MS candidate Visiting scholar in SACNlab Northwestern University