there is a mistake in the graph, hippocampal volume is TIV2 I apologize for that!
Angela Favaro <angela.fav...@unipd.it> ha scritto: > Hi Bruce, > please find attached the graph of the correlation between the two time > point. I did not find outliers or failures. However the discrepancy > between TIVs is particularly high in few cases. Obviously these data > are those before running longitudinal streaming > This is a sample of adolescents with low body weight (anorexia nervosa). > In my previous study (on young adults with low weight) I found no > correlation between TIV and body weight and high correlations between > fs estimated TIV and manually segmented TIV (r=0.94 in the whole > sample and r=0.93 in the underweight sample (n=38)). > Do you think that the young age can be a factor? or patients who are > more acutely underweight? > Thank you for any suggestion > > Angela > > > Bruce Fischl <fis...@nmr.mgh.harvard.edu> ha scritto: > >> Hi Angel >> >> the time1/time2 correlation of eTIV is pretty worrisome. Are you sure >> that there aren't outliers/failures in that set? >> >> Bruce >> >> >> On Sun, 14 Feb 2016, angela.fav...@unipd.it wrote: >> >>> Dear Freesurfer experts, >>> I have a question about eTIV (FS 5.3) which I use as a covariate where >>> appropriate. Is it in some way influenced by the presence of brain >>> atrophy? >>> I have a new sample of subjects in a longitudinal study: at time 1 they >>> have some atrophy (due to low body weight) that improves in time 2 (4 >>> months). I observed that eTIV-time1 is slightly correlated with weight >>> (r=0.3) whereas no correlation is present at time 2. The correlation >>> between eTIV-time1 and eTIV-time2 is somewhat lower than expected (r=0.53) >>> and is lower than correlation between SegBrain_Vol_1 and SegBrain_Vol_2 >>> (0.65). >>> >>> Do you suggest in these cases to perform manual segmentation to obtain >>> TIV? or is there any other method (in freesurfer) to obtain an estimate of >>> TIV not influenced by brain atrophy? What about using BrainMask_to_TIV? >>> >>> Thank you for any suggestion >>> >>> Angela >>> >>> >>> _______________________________________________ >>> Freesurfer mailing list >>> Freesurfer@nmr.mgh.harvard.edu >>> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer >>> >>> >>> >> _______________________________________________ >> Freesurfer mailing list >> Freesurfer@nmr.mgh.harvard.edu >> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer >> >> >> The information in this e-mail is intended only for the person to whom it is >> addressed. If you believe this e-mail was sent to you in error and >> the e-mail >> contains patient information, please contact the Partners Compliance >> HelpLine at >> http://www.partners.org/complianceline . If the e-mail was sent to >> you in error >> but does not contain patient information, please contact the sender >> and properly >> dispose of the e-mail. _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
