ABCD Neuroimaging Protocol Harmonization

Extensive details of the ABCD neuroimaging acquisition sequences and processing streams have been presented elsewhere (Casey et al. 2018 (link); Hagler et al. 2019 (link)). Our analyses focused on metrics extracted from the Desikan-Killiany (DK) and Destrieux Atlases implemented in Freesurfer, with evidence that identification of the features on which these atlases are based works well down to age 4 (Ghosh et al. 2010 (link)). The ABCD imaging protocol was harmonized across data collection sites for three 3T scanning systems (Siemens Prisma, Philips, General Electric 750), all of which used standard adult-size multi-channel head coils and multiband echo planar imaging (EPI) acquisitions. The diffusion MRI acquisition had high resolution (1.7 mm isotropic voxels) and utilized multiband EPI (Hagler et al. 2019 (link)). The scanning sequences that yield structural data (Casey et al. 2018 (link)) include a localizer, T-1 weighted scan, diffusion tensor imaging (DTI), and T-2 weighted scans. Real-time motion detection and correction during acquisition are implemented by customized hardware and software. Imaging parameters were harmonized as much as possible between scanner manufacturers.