Dear FSL Experts,
I am trying to compare FA AD MD and RD values in a cohort divided by age into 6 different age bins. However, three combinations produced blank tbss_tfce_corrp images, and when I looked into the tbss_logs, there was the warning message:
Warning: The unpermuted statistic image for the current image contains no positive values, and cannot be processed with TFCE. A blank output image will be created.
I have checked the original images and the processed FA images and they seem to be fine.
As an example, one of my contrasts that did not work had this mat and con file:
e.g.1 This was a comparison between ages 31-40 against ages 41+, covarying for sex.
/NumWaves 3
/NumPoints 30 30 30
/PPHeights 1 1 1
/Matrix
2v3+4
1 0 0
[...]
1 0 1
/NumWaves 3
/NumContrasts 2
/PPheights 1 1 0
/Matrix
1 -1 0
-1 1 0
Is there anyway to work around this error and do these comparisons?
Thank you for your time,
Alex
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