Table 1. Some key parameters in diffusion imaging.

Diffusion time Δ	Longer Δ results in more attenuation in diffusion signal
Gradient strength G	Stronger G results in more attenuation in diffusion signal
	Summarizes the effect of gradient strength and diffusion time, where γ is the gyromagnetic ratio (a constant) and δ is the duration of gradient encoding
Single-shell dMRI	Varying gradient directions with a fixed b-value
Multi-shell dMRI	Varying gradient directions with a small set of b-values. Three different b-values were used in HCP protocol

Abbreviations: dMRI, diffusion MRI; HCP, Human Connectome Project.