TABLE 1.

Summary of the proposed anisotropic diffusion metrics

Measure	Formula	Practical implementation
APA	$\gamma \left({\text{APA}}_0,ϵ\right)$	$\gamma \left({\text{APA}}_0,ϵ\right)$
${\mathrm{APA}}_0$	$\sqrt{1‐\frac{{\left[{\int }_S{(D(\mathbf{u})+D_{\mathrm{AV}})}^{‐3/2}d\mathbf{u}\right]}^2}{\sqrt{2}\pi D_{\mathrm{AV}}^{‐3/2}{\int }_S{(2D(\mathbf{u}))}^{‐3/2}d\mathbf{u}}}$	$\sqrt{1‐\frac{4}{\sqrt{\pi }}\frac{{\left[C_{0,0}\left\{{(D(\mathbf{u})+D_{\mathrm{AV}})}^{‐3/2}\right\}\right]}^2}{C_{0,0}\left\{D{(\mathbf{u})}^{‐3/2}\right\}·D_{\mathrm{AV}}^{‐3/2}}}$
$D_{\mathrm{AV}}$	$\frac{1}{4\pi }{\int }_{S}D(\mathbf{u})d\mathbf{u}$	$\frac{1}{\sqrt{4\pi }}{C}_{0,0}\left\{D(\mathbf{u})\right\}$
DiA	$\sqrt{\frac{4\pi ·{\int }_S{D}^2(\mathbf{u})d\mathbf{u}‐{\left[{\int }_{S}D(\mathbf{u})d\mathbf{u}\right]}^2}{4\pi ·{\int }_S{D}^2(\mathbf{u})d\mathbf{u}}}$	$\sqrt{1‐\frac{\frac{1}{\sqrt{4\pi }}·C_{0,0}^2\{D(\mathbf{u})\}}{C_{0,0}\{D^2(\mathbf{u})\}}}$