Dear Maxim, > it seems that after eddy_correct my data.nii and > nodif_brain_mask.nii have > different dimensions. fslview wont't load them together, and spm > checkreg > shows them completly spatialy unregistered. is that normal- -or > might this > be the problem for strange FA maps after dti fit ? I had a look at your data before and after eddy_correction, and it hasn't worked very well. I have a feeling that you left 0 as reference volume. I tried using 1 instead, the diffusion weighted volume, and the results look much better. I then used bet (with -f 0.3) to generate a brain mask and fit it all into dtfit. There is one slice with some problems (you should look through the individual dwi's for that slice), but on the whole a very nice looking FA map. Good Luck Jesper