@Anaelle, could you run CAT12 on the MRI from the Default anatomy? Follow these steps:
- Create a new subject (default anatomy: NO, default channel file: NO)
- Right-click on subject folder > Use template > ICBM152
- Delete all the surfaces, keep only the MRI
- Right-click on MRI file > MRI segmentation > CAT12
- Use the same settings in CAT12 as you are doing with your MRI file