Dear Freesurfer experts,
I am working on a longitudinal analysis of cortical structure and am experiencing some errors with registration. I have 3 timepoints for each participant:
time 1: age 2 time 2: age 5 time 3: age 10
Time 1 and 2 are from a 1.5T scanner. Time 3 is from a 3T scanner.
Despite the age range and scanner difference, the registrations in the longitudinal pipeline (I'm using version 5.3) are performing relatively well. However, in comparing the LONG outputs slice by slice, it appears that in a majority of my subjects, there are some minor mismatches in brain anatomy. An example is attached here (minor_reg_error.jpg).
In other instances, there are more substantial registration errors. Again, example attached here (major_reg_error.jpg).
My question is how much mismatch is acceptable? And how can I go about fixing poor registrations in subjects who have significant errors in alignment?
Many thanks in advance, Lara
Lara Foland-Ross, Ph.D. Research Associate Center for Interdisciplinary Brain Sciences Research Stanford University School of Medicine 401 Quarry Road, Room 1356 Stanford, CA 94305-5795
