[MINC-users] Failure of nu-estimate on older t1-weighted brain data.

[Najmeh Khalili M.]

Greetings,

I am trying to perform N3 on t1-data of healthy older brains and I
encounter two error messages. (nu_estimate, version 1.10)

First, I got the following error for N=50 data sets:

 Assertion failed at line 742 in file templates/CachedArray.cc
 nu_estimate_np_and_em: crashed while running volume_stats (termination
status=256)

Next, I used an ICBM mask; succeeded in non-uniformity correction of N=45
data sets, but failed in 5 with :

  Direction cosines of mask.mnc and /tmp/native_t1.mnc do not match
  Failed to shrink mask volume.
  nu_estimate: crashed while running nu_estimate_np_and_em (termination
  status=65280)

The data dimension in the failed cases is identical to those that have
succeeded. The data quality and the brain structure in failing cases is
not visually different. I have not seen this problem in younger brains.

Has someone else experienced such errors and can any one give an
explanation of what the cause of this might be, please?

Best,
Najma