CAT12 does not preproces all images and fails to create symbolic links

I have a dataset that contains 270 T1-weighted images that I want to preprocess using CAT12. However, CAT12 only manages to preprocess 180 out of 270 images. Though, in the console it says:

Conclusion: 
  Processed successfully:     180 volume(s)
  Processed with error:         0 volume(s)

In case of warnings and errors please check the correct position
of the AC by using the SPM display function.

I checked the err directory which is created by CAT12 and I can only find information (.txt, .xml, .pdf) for 12 files. I also checked the .log files. It seems that CAT12 is unable to copy files and/or create symbolic links for some files:

CAT Preprocessing error for sub-A00036503_ses-20060101_acq-mprage_run-01_T1w:
------------------------------------------------------------------------
Bad tissue contrast (BG=49.76, CSF=109.18, GM=108.51, WM=139.88): 
  This can be the result of (i) an improper SPM segmentation caused by 
  failed affine registration, (ii) improper image properties with low 
  contrast-to-noise ratio, or (iii) by preprocessing error. 
  Please check image orientation and quality. 
------------------------------------------------------------------------
  372 - cat_main_gintnorm1639
  113 - cat_main1639
  884 - cat_run_job1639
   33 - cat_run_newcatch
  865 - run_job
  455 - cat_run
------------------------------------------------------------------------

Print 'Graphics' figure to: 
  /CSP/analyses/johannes.wiesner/projects/sfam/data/schizconnect/cobre_mcic_t1_query/cobre_mcic/MCIC/derivatives/MCIC_Site_A/preproc_cat12/report/catreport_sub-A00036503_ses-20060101_acq-mprage_run-01_T1w.pdf
{ Error using cat_check_system_output (line 27)
ln: failed to create symbolic link
''/CSP/analyses/johannes.wiesner/projects/sfam/data/schizconnect/cobre_mcic_t1_query/cobre_mcic/MCIC/derivatives/MCIC_Site_A/preproc_cat12/err/cat_main_gintnorm1639.line372.cat_main.badTissueContrast/sub-A00036503_ses-20060101_acq-mprage_run-01_T1w.nii'':
Operation not supported


Error in cat_run_newcatch (line 239)
          cat_check_system_output(ST,RS,job.extopts.verb>2);

Error in cat_run>run_job (line 865)
      cat_run_newcatch(job,tpm,subj);

Error in cat_run (line 455)
varargout{1} = run_job(job);
}

Can someone help with this? Pinging @Christian_Gaser here, maybe he knows what’s going on?

Dear @JohannesWiesner,

you have split the calculation of your data into 3 jobs and in one job there occur errors and this will stop preprocessing of the remaining files. There is an option in CAT12 to move on if errors occur. However, I suspect that you are using an older CAT12 version (please always provide your release number). The “bad tissue contrast” error should occur more rarely with the newest release.

Best,

Christian

Hi @Christian_Gaser, I am using CAT12.7 (r1720) from 2020-09-21. If I am not mistaken, the ‘continue with next subject’-option is set as default in this version? The only changes from my side where selecting the images and splitting the task into 18 jobs.

Hi @JohannesWiesner,

then I could only suggest to check file permissions and use a clean installation of the newest version and try again processing of the remaining files.

Best,

Christian

1 Like

The solution to the problem was quite straight forward. As reported in the error message, MATLAB was not able to create symbolic links (ln: failed to create symbolic link), because my IT department simply hadn’t allowed it on the filesystem I am working on. After enabling this, everything worked.