Coordinate Space Transforms for Neuroimaging Templates

Functions and constants for transforming coordinates between standard neuroimaging coordinate spaces, particularly MNI305 (fsaverage) and MNI152 (common fMRI template space).

Value

This documentation topic describes legacy coordinate-family constants and affine helpers. Use exact template identifiers for qualified registration.

Details

These legacy helpers classify broad coordinate families and apply a fixed FreeSurfer affine. They do not establish template-specific registration or cortical correspondence. Use exact MNI template identifiers and qualified transforms for image resampling or population cortical projection.

Coordinate Spaces

MNI305

FreeSurfer/Talairach space. Native space for fsaverage, fsaverage5, and fsaverage6 surfaces. Based on 305 subjects with linear registration to approximate Talairach space.

MNI152

A broad coordinate-family label. MNI152NLin6Asym and MNI152NLin2009cAsym are distinct templates; this shorthand does not identify either variant or a registration between them.

References

FreeSurfer CoordinateSystems documentation: https://surfer.nmr.mgh.harvard.edu/fswiki/CoordinateSystems

Wu et al. (2018). Accurate nonlinear mapping between MNI volumetric and FreeSurfer surface coordinate systems. Human Brain Mapping, 39(9), 3793-3808. doi:10.1002/hbm.24213

Examples

transform_coords(matrix(c(0, 0, 0), nrow = 1),
  from = "MNI305", to = "MNI152"
)
#>         [,1]   [,2]  [,3]
#> [1,] -0.0429 1.5496 1.184