[Freesurfer] Using SPM transformation matrices as initial guess in talairach_avi

Hello,

since I experienced a high rate of registration errors using talairach_avi in the conventional recon-all processing stream (more than 50% misregistration), I would like to incorporate SPM affine registration parameters (as provided in the seg_inv_sn.mat file obtained from the segmentation routine) as initial guess "to help" talairach-avi. Is there a possibility to do this? How do I have to adjust the transformation matrix that it can be handled by freesurfer?

I also tried to circumvent the registration-problem using skull-stripped images, which unfortunately also did not improve the results (I think a template made from skull-stripped images has to be used in that case)

Any help would be much appreciated

Regards, Simon