What's the difference between registration to MNI and reorientation to MNI?

  • reorient the images to the standard (MNI) orientation [fslreorient2std]
  • automatically crop the image [robustfov]
  • bias-field correction (RF/B1-inhomogeneity-correction) [FAST]
  • registration to standard space (linear and non-linear) [FLIRT and FNIRT]
  • brain-extraction [FNIRT-based or BET]
  • tissue-type segmentation [FAST]
  • subcortical structure segmentation [FIRST]

Hi @Yasmine,

Reorientation like in fslreorient2std implies the labels (e.g., superior, inferior, etc) are switched to match a convention (e.g., RAS or LPS), but the brain is not warped. It might also imply just a rigid rotation where the brain is not scaled at all.

Registration might mean a more complex operation is happening, in which the brain might be scaled and rotated to match a standard space.