Dear SPM community,
After running the 'Estimate & write' module with the VBM8 toolbox and looking at the 'Sample Homogeneity' (module 3), I have noticed that there is a bit of dura remaining on the peripherally of most brains. Is this normal? This includes outliers but seem to occur when looking at the "non outliers"?
And if not, how can I adjust the parameters in VBM8 to remove these artefacts? In what proportion of the presence of dura within the GM mask is tolerated, if tolerated?
Also following the sample homogeneity step, when checking for outliers, what kind of structural features classify a brain as an outlier? When checking the GM mask the only obvious issue I saw was a little bit of remaining dura on the periphery, as well as "brightness" in subcortical regions (i.e. caudate, thalamus). However, when checking scans which had high covariance there was also a bit of dura remaining. So I'm a bit confused why VBM has marked these brains as outliers (is it to do with contrast intensity rather than structural irregularities or something else?)
Thank you for your help in advance.
-Nina
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