Fig. 6.

The four 3D signal types $\mu \left(\mathit{s}\right)$, from top-to-bottom: small sphere, large sphere, multiple spheres, and the UK Biobank full mean image. Note that the colormap limits for the first three signal types are from 0 to 3, while the colormap limits for the UK Biobank mean image is from −0.4 to 0.5.