MRI datasets of 10 healthy volunteers in the age range of 22–35 (6 female, 4 male) were obtained from the HCP Wu-Minn database (https://db.humanconnectome.org ). Only non-restricted, anonymized open access datasets were used. Therefore, no ethical consent is necessary according to national laws and regulations. Subjects were scanned at a Siemens 3T scanner equipped with a dedicated, high performance gradient system capable of gradient strengths of 100 mT/m with special gradient amplifiers (Ugurbil et al., 2013 (link)). Three shells with b-values of 1,000, 2,000, and 3,000 s/mm2 were acquired with 90 diffusion encoding directions on each shell. The spatial resolution was 1.25 mm isotropic. Two phase-encoding direction reversed images for each diffusion direction were acquired. The non-diffusion weighted volumes with b = 0 were interleaved with DW volumes such that every sixteenth volume had no diffusion weighting. More details about the acquisition protocol can be found in Sotiropoulos et al. (2013 (link)).
The utilized diffusion datasets were already preprocessed by the HCP diffusion pipeline (Glasser et al., 2013 (link)). Briefly, distortions were corrected using a model-based approach that simultaneously takes into account susceptibility and eddy-current induced distortions, as well as head motion.
The utilized diffusion datasets were already preprocessed by the HCP diffusion pipeline (Glasser et al., 2013 (link)). Briefly, distortions were corrected using a model-based approach that simultaneously takes into account susceptibility and eddy-current induced distortions, as well as head motion.