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

The χ-separation atlas provides normative maps of paramagnetic susceptibility (χ_para) and diamagnetic susceptibility (χ_dia) derived from 106 healthy human brains. For more details, refer to Min et al., NMR Biomed., 2024.

Features

• χ-separation templates
  • Accompanied by T₁-weighted and hybrid templates
• ROI labels
  • With associated χ-separation statistics
• MNI space registration
  • All templates are registered to the MNI ICBM-2009c asymmetric T₁-weighted image template

Note: The χ_dia atlas is provided in absolute values.

Contents

• Templates

  File name	Description	Unit
  chi_para	χpara map	ppm
  chi_dia	χdia map	ppm
  chi	QSM map	ppm
  t1w	T1-weighted image	a.u. (0–1)
  hybrid	Hybrid image	a.u. (0–1)

• Labels

  File name	Description	Unit
  labels	8 subcortical nuclei, 3 thalamic nuclei, and 13 white matter	N/A
  label_names	Indexes and names of labels	N/A
  prior_WM	Population average of white matter masks	a.u. (0–1)
  prior	Population average of brain masks	a.u. (0–1)

• Atlas statistics

  File name	Description	Unit
  chi_para_rSD	Relative SD map of χpara	N/A
  chi_dia_rSD	Relative SD map of χdia	N/A
  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	62.1 ± 15.8	47.5, 65, 76.5	27–85
Sex	37 males and 79 females

License

This software and its documentation are provided for academic research purposes only. They are not intended for commercial or clinical use.

---

Acknowledgments

Subcortical nuclei, thalamic nuclei, and white matter labels are adapted from MuSus-100 and ICBM-DTI-81.

Version: v1.2.0
Last Updated: 2024/10/31

---