chi-separation atlas (χ-separation atlas, x-separation atlas)

χ-separation atlas provides normative paramagnetic susceptibility (χ_para) and diamagnetic susceptibility (χ_dia) maps from 106 healthy human brains.

Features

• χ-separation templates, accompanied with T₁-weighted and hybrid templates
• ROI labels and χ-separation statistics
• NIfTI (NIfTI/*.nii.gz) and DICOM (DICOM/*.zip) formats are available
• Registered to MNI space (ICBM-2009c asymmetric T₁-weighted image template)

Note that χ_dia is in absolute value.

Contents

• Templates

  File name	Description	Unit
  chi_para	χpara map	ppb
  chi_dia	χdia map	ppb
  t1w	T1-weighted image	a.u. (0–255)
  hybrid	Hybrid image	a.u. (0–255)

• Labels [1]

  File name	Description	Unit
  labels	5 subcortical nuclei and 14 white matter fiber bundles	N/A
  label_names	Indexes and names of labels	N/A
  prior_WM	Population average of white matter masks	a.u. (0–255)
  prior	Population average of brain masks	a.u. (0–255)

• Atlas statistics

  File name	Description	Unit
  chi_para_rSD	Relative SD map of χpara	%
  chi_dia_rSD	Relative SD map of χdia	%
  chi_para_ROI_stats	Mean and SD of χpara in ROIs	ppb
  chi_dia_ROI_stats	Mean and SD of χdia in ROIs	ppb

Demographics

	Mean ± SD	Quartiles	Range
Age	60.8 ± 15.8	46, 64, 75	27–85
Sex	34 males and 72 females

License

We provide this software and its documentation for academic research purposes only, and it is NOT intended for commercial or clinical use.

---

[1] Subcortical nuclei and white matter labels are adapted from MuSus-100 and ICBM-DTI-81
For more details, see (upcoming) preprint.
v1.0.0 | Last update: 2023/09/15