Hi, I’ve finished processing a data set that included longitudinal data and I’m having a problem with a small percentage of the longitudinal timepoints.  To review what I’ve done, I edited all of the individual (cross-sectional) timepoints until the wm and pial surfaces were correct, then created the base and edited that until it looked good, and then created the longitudinal files for each cross-sectional timepoint.  Most of these did not need editing and some needed slight edits to either wm or brainmask which corrected the longitudinal surfaces. 

 

However, in a small handful of cases, the wm/pial surfaces were so distorted that editing would not fix the problem.  In these cases, longitudinal surfaces were very different from both the original cross-section and base.  I’ve tried to attach a file that shows an example – it might only affect a small portion of the brain but in these cases I don’t think I could edit it to improve the surfaces.  In the example I attached, red/blue are from the long file and pink/lt blue are from the base.

 

Do you have any suggestions for why this might be happening and how to fix it?  I’m running v6.0.

 

Thanks!

Laura Danielian