Hi,
It is possible that you do have left hemisphere changes in radial/axial diffusivity but that they are sub-threshold. Instead of only looking at the thresholded results, I suggest that you examine the unthresholded results in the areas that you saw significant changes in FA and MD, in order to see if these correspond with changes in axial/radial diffusivity changes that just failed to meet the threshold for statistical significance on their own. You can still use the unthresholded values to help you interpret the FA/MD changes.
All the best,
Mark
On 19 Jun 2014, at 23:41, Angela Favaro <[log in to unmask]> wrote:
> Hi all,
> I have some doubts about my results after comparing using the TBSS methods
> my pathological sample with a control group (of similar age, education,
> hand-lateralization and gender).
> I found an area of significantly decreased FA in the left hemisphere and
> nothing in the right hemisphere. In the same area (Left H), MO was
> significantly decreased, too. However, when I analysed axial and radial
> diffusivity, I found areas of significantly increased diffusivity only in
> the right hemisphere (one of these areas was the right fornix).
> I wonder if this is due to some problem in my analyses or if I only have
> to find some interpretation of these findings. My expectations were to
> find at least some overlapping between 'alterations' of the different
> indices.
>
> Thank you for any comment
>
> Angela
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