Diffusion Atlas

# Fetal Diffusion Atlas Re-release of the Khan et al. (2019) fetal diffusion atlas (reference below) with added tissue segmentations and regional parcellations for gestational age (GA) weeks 22 through 35. ## Contents This dataset contains diffusion atlas images for gestational age weeks 22 through 38. The diffusion atlas reconstructions were computed in separate coordinates as compared to the CRL2025 T2 atlas. These files are referred to as \"DWI-space\", are located in the \"DWIspace\" folder, and individual files have the prefix \"dwi-dspace\". We performed affine registrations moving T2-space images using the diffusion atlas FA images as the target, and then applied the inverse transform resulting in \"T2-space\" diffusion atlas images. These can be found in the \"T2space\" folder, and individual files have the prefix \"dwi-t2space\". Affine transforms, converted to MRtrix format, going from T2-space to DWI-space can be found in the \"transformations\" folder. Tissue and regional segmentations were fitted to diffusion atlases using diffeomorphic registration of T2 atlas images to the diffusion atlas, and then modified by hand for research purposes and have been made available here. Only GA weeks 22 through 35 are available at this time. File suffixes: _b0 - b0 signal reconstruction _b1 - b1 signal reconstruction _tensor - Reconstructed tensor image Diffusion scalar images derived from tensor: _fa - Franctional anisotropy _cfa - Color FA _md - Mean diffusivity _tissue - Tissue segmentation _region - Regional segmentation _T2toFA_mrtrix.txt - MRtrix format T2 to diffusion space transform DWIAtlas_labelkey.txt - ITK-SNAP label key for Tissue and Regional segmentations ## License/Data Use Agreement These files are published under CC BY 4.0: https://creativecommons.org/licenses/by/4.0/ Files in this data release were developed for research purposes and are not intended for medical or diagnostic use and have no warranty. The authors and distributors do not make any guarantees regarding the accuracy or usefulness of results generated from these tools or their derivatives, and are not liable for any damages resulting from their use. Through this data use agreement, you agree to cite the DOI referring to this resource as well as the following work: Bagheri, M., Velasco-Annis, C., Wang, J., Faghihpirayesh, R., Khan, S., Calixto, C., Jaimes, C., Vasung, L., Ouaalam, A., Afacan, O. and Warfield, S.K., 2025. An MRI Atlas of the Human Fetal Brain: Reference and Segmentation Tools for Fetal Brain MRI Analysis. arXiv preprint arXiv:2508.15034. Khan, S., Vasung, L., Marami, B., Rollins, C.K., Afacan, O., Ortinau, C.M., Yang, E., Warfield, S.K. and Gholipour, A., 2019. Fetal brain growth portrayed by a spatiotemporal diffusion tensor MRI atlas computed from in utero images. Neuroimage, 185, pp.593-608. Khan, S., Rollins, C.K., Ortinau, C.M., Afacan, O., Warfield, S.K. and Gholipour, A., 2018. Tract-specific group analysis in fetal cohorts using in utero diffusion tensor imaging. In Medical Image Computing and Computer Assisted Intervention–MICCAI 2018: 21st International Conference, Granada, Spain, September 16-20, 2018, Proceedings, Part III 11 (pp. 28-35). Springer International Publishing.