Main question is in the topic line.
I know that there is a difference, but I have not been able to find a clear answer as to what that difference is by googling or by asking around with my colleagues.
I know that NLin6 is an FSL distribution, and that NLin2009c is the default output from fmriprep. How do they differ? Why are they both used? What manipulations or registrations need to be performed in order to use them together? Can they be used interchangeably? What effects and differences can you expect to encounter if you try to use them interchangeably?
Basically any information that would add to the understanding of what these templates are trying to accomplish would be greatly appreciated!
Thanks in advance!
Two good resources are About the MNI space(s) – Lead-DBS and Coordinate systems - Brain Imaging Data Structure 1.10.0 . The first figure in the lead-dbs shows the MNI152NLin6Asym vs one of the 2009 templates, giving an idea about how much they can differ in size.
Note that templateflow provides transformations that could be used to move an image from one space to another, e.g.,
- tpl-MNI152NLin2009cAsym/tpl-MNI152NLin2009cAsym_from-MNI152NLin6Asym_mode-image_xfm.h5
I think it’s generally preferable to avoid using them interchangeably (though whether it matters for results likely depends on the analysis and preprocessing steps like amount of smoothing), and any methods section should include a description of which spaces were used and how images were transformed (if images were moved between the two).
Do those resources help?