Martin,
Which version of freesurfer did you use to generate the surfaces? Because the number of topological defects in your surface (64) is very high. You may have to relaunch the surfaces (orig and pial) to get better surfaces (i.e. 0 defect).
Lgi often fail if there are defects, sometimes it will pass if you relaunch it, but if there are numerous defects the algorithm is not able to cope with it.
Marie
Quoting Martin Kavec martin.kavec@gmail.com:
Hi,
I get the following warning followed by error in LGI calculation:
... remeasuring lGI value for vertex iV = 6301. It may take a few minutes. WARNING -- Problem for vertex iV = 6301, lGI value is aberrantly high (lGI=48.6447)... ...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 'tmp-mris_compute_lgi/rh.pial_lgi.asc'! Linux antarctica 2.6.24-gentoo-r8 #1 SMP Sat May 17 14:07:35 CEST 2008 x86_64 Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz GenuineIntel GNU/Linux
recon-all exited with ERRORS at Sun May 25 09:22:16 CEST 2008 ________________________________________________________
The suggested mris_euler_number gives: ________________________________________________________ mris_euler_number rh.pial euler # = v-e+f = 2g-2: 155756 - 467454 + 311636 = -62 --> 32 holes F =2V-4: 311636 != 311512-4 (-128) 2E=3F: 934908 = 934908 (0)
total defect index = 64 ________________________________________________________
If I just rerun the LGI calculation, as suggested on the LGI web page, the calculation stops at exactly the same place. I am not sure, if I understand the execution correctly in this case, but while observing the commands, one of the first ones is removing the tmp-.... in the surf directory.
Can anybody suggest me please, how to correct the defect in that particular vertex. The topological defect repair described on the web deals with dura matter pixels removal.
Thanks in advance,
Martin _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer