This is Tracula 5.2 with FLIRT and the vectors are correctly aligned (V1 over FA). From the literature and what is seen in my TBSS is reduced FA in the minor forceps and ATR.

These are young (23yo) psychiatric so age related atrophy is not expected. However, they are known to have WM hypointensities even at a young age, I can review their T2s. A few are on mood stabilizers, but if this affected FA I would also see it in TBSS. Thoughts?

Anastasia Yendiki <ayendiki@nmr.mgh.harvard.edu> wrote:


Oh, another question: do your patients have white-mater
hypo/hyper-intensities, in other words any voxels in the white matter that
are classified as something other than white matter in the freesurfer
aseg?

On Wed, 3 Apr 2013, Sean Hatton wrote:

> Hi Freesurfer gurus,
>
> I have been using Tracula to investigate white matter abnormalities in a patient
> cohort (n=20) compared to matched controls (n=40). In line with the literature, we
> expected to see reductions in FA in the patients' tracts but instead they have
> significantly higher FA means. To double-check, we ran TBSS over the same cohorts and
> got the results as per the literature (I.e. reduced FA in the patient group). The FA,
> RD, AD, MD and volume outputs are normally distributed and there are no extreme
> outliners. So wondering:
>  1. The patient group had significantly reduced tract volumes. If this volume
>     calculation is incorrect I expect it could influence the calculation of the mean
>     FA, RD, AD etc. Is there a way of checking the volume and subsequent
>     calculations? 
>  2. Yendiki et al 2011 had no corrections – do I need corrections? 
>  3. Should I be thresholding tract stats?
> Thank you in advance,
>
> Sean Hatton
> Brain and Mind Research Institute
> University of Sydney
>
>
>
>
>
>
>


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.