Dear freesurfer users,

I run the command *'recon-all -lgi' *for my participants and for two of them I get the following error message:

... remeasuring lGI value for vertex iV = 39301. It may take a few minutes. WARNING -- Problem for vertex iV = 39301, lGI value is aberrantly high (lGI=44.2971)... ...lGI computation will be stopped. This may be caused by topological defects, check mris_euler_number on the pial surface.

ERROR: compute_lgi did not create output file '/data_august/Geo/freesurfer_OCD/subjects_converted/KuTo67/surf/tmp-mris_compute_lgi-lh.pial/lh.pial_lgi.asc'!

On the freesurfer weppage (http://freesurfer.net/fswiki/LGI), it is supposed to be a known issue and they suggest to relaunch *mris_compute_lgi *, quote: /In case of topological defects of the pial surface (run mris_euler_number), mris_compute_lgi crashes. Usually, simply relaunching mris_compute_lgi is sufficient to overcome this issue. /

I already tried that several times and i still get the same error . The script always crashes at the same vertex. However when I check the mris_euler_number for the subject's rh.pial it interestingly does not show me any topological defect.

Has anybody encounter the same problem? or what should be a possible solution?

Thanks a lot in advance for your answer.

Best Georgiana