SACT template

We establsihed the SACT template by using a large sample of diffusion data of school-age children (380 participants). We provided two types of diffusion tensor (DT) templates. One is for the entire age range (6-12 years old), another one is for each specific age.Under the downloaded data, four folders are corresponding to different kinds of templates. Specifically, SACT includes the tensor template of the entire age range (‘SACT_06_12_DT.nii.gz’) which is in the same space as the CHN-PD template (https://helab.bnu.edu.cn/chn-pd/). The corresponding fractional anisotropy (FA) and trace map (3*Mean diffusivity, MD) are also available (‘SACT_06_12_DT_fa.nii.gz’, ‘SACT_06_12_DT_tr.nii.gz’). The ‘SACT_06_12_mask.nii.gz’ is the brain mask. Similarly, age-specific templates can be found in the age-specific folders, e.g., ‘/Age_Specific_SACT/Age_06_07’. Here, ‘06_07’ stands for the age range between 6 years old and 7 years old. To conveniently use the SACT template with tensor-based registration methods (DTI-TK), we also provided the corresponding templates which are padded with zeros to ensure the matrix size of the template as 256*256*256, which are available under the folders ended with ‘DTI_TK’.Moreover, the tensor templates are organized as six tensor components stored in the lower triangular order, i.e., Dxx, Dyx, Dyy, Dzx, Dzy, and Dzz. It is in the same order as the one specified by the NIfTI standard. The unit of diffusivity is 10-3mm2.s-1.Finally, to conveniently and accurately use the SACT template for the TBSS (ref. 1) analysis, we provided the ‘SACT_LowerCingulum_1mm.nii.gz’ under the ‘TBSS’ folder of each template. As the mask of the lower cingulum would be required for the skeleton process (ref. 1), we compensated the difference between SACT template and FMRIB58_FA template by registering the FMRIB58_FA template to the corresponding SACT template. Then, the warp field were applied to the mask of the lower cingulum corresponding to the FMRIB58_FA template.<br>Ref.1:S.M. Smith, M. Jenkinson, H. Johansen-Berg, D. Rueckert, T.E. Nichols, C.E. Mackay, K.E. Watkins, O. Ciccarelli, M.Z. Cader, P.M. Matthews, and T.E.J. Behrens. Tract-based spatial statistics: Voxelwise analysis of multi-subject diffusion data. NeuroImage, 31:1487-1505, 2006.