DHr:	The diameter–height ratio, an expression of the fusiform shape of the AAA sac
	$$\mathit{DHr}=\frac{D_{max}}{H_{\text{neck}}+H_{\text{sac}}}$$
DDr:	Diameter–diameter ratio
	$$\mathit{DDr}=\frac{D_{max}}{D_{\text{neck},\text{p}}}$$
Hr:	Height ratio, an assessment of the relative neck height in comparison with the AAA height
	$$Hr=\frac{H_{\text{neck}}}{H_{\text{neck}}+H_{\text{sac}}}$$
BL:	Bulge location, provides a measure of the relative position of the maximum transverse dimension with respect to the neck
	$$BL=\frac{H_{\text{b}}}{H_{\text{neck}}+H_{\text{sac}}}$$
β:	Asymmetry factor
	$$\beta =1-\frac{d_{\text{c}}}{D_{max}}$$
T:	Tortuosity
	$$T=\frac{L_{\text{neck}}+L_{\text{sac}}}{d}$$