Re: [Freesurfer] FA and MD *positively* correlated within same regions ?

I think eroding the region makes sense in general - you just have to be careful to exclude subjects who end up with no data (as you discovered!) You could also look into why these three subjects had such small wm regions under entorhinal cortex. My (still) suspicious mind wonders if there is a

Re: [Freesurfer] FA and MD *positively* correlated within same regions ?

Hi Elijah - I suggest looking at the axial diffusivity (AD) and radial diffusivity (RD) to help you interpret these results. These are the diffusivity parallel and perpendicular to the main budnle going through a voxel, respectively. Essentially, FA tells you how different the AD and RD are

Re: [Freesurfer] FA and MD *positively* correlated within same regions ?

Hi Kirstie, Yes indeed there were 3 subjects at the bottom-left of the plot. To account for PV, I eroded the boundaries using *-seg-erode 1* during the *mri_segstats* stage, and this resulted in a few subjects with no data for the WM entorhinal region (although these were saved as "0" in the

Re: [Freesurfer] FA and MD *positively* correlated within same regions ?

Hi Elijah, Is there any chance you could attach a scatter plot? My suspicious mind thinks either a) there are outliers who are doing odd things, or b) the FA values are very different to those in other regions and therefore the correlation with MD wouldn't be expected to be the same. Kx

Re: [Freesurfer] FA and MD *positively* correlated within same regions ?

Hi Alshikho , Yes, I am sure :) Same sequence for everyone. Just to add. FA and MD were significantly negatively correlated for the other regions including the fusiform, precuneus,

Re: [Freesurfer] FA and MD *positively* correlated within same regions ?

To: Freesurfer support list Subject: [Freesurfer] FA and MD *positively* correlated within same regions ? Hi Freesurfer Community, I recently used mri_segstats to extract FA and MD as suggested here: http://freesurfer.net/fswiki/FsTutorial/Diffusion Using the aparc+aseg and wmparc (resampled

[Freesurfer] FA and MD *positively* correlated within same regions ?

Hi Freesurfer Community, I recently used mri_segstats to extract FA and MD as suggested here: http://freesurfer.net/fswiki/FsTutorial/Diffusion Using the aparc+aseg and wmparc (resampled to diffusion space), I looked at some of the correlations between FA and MD in the same regions, and came