Table 3.

Definition and calculation of indices.

Index	Symbol	Description
Area ratio index of left lung	$R_l$	$\frac{A_{H,l}}{A_l}$
Area ratio index of right lung	$R_r$	$\frac{A_{H,r}}{A_r}$
Temperature index of left lung	$T_l$	average $T_i$ of the left lung
Temperature index of right lung	$T_r$	average $T_i$ of the right lung
Standard deviation of left lung	$S_l$	std of $T_i$ of the left lung
Standard deviation of right lung	$S_r$	std of $T_i$ of the right lung
Distance index of left lung	$P_l$	$\frac{{\sum }_{i=1}^{A_{H,l}}{(d_{l,\mathit{spine}})}_i}{A_{H,l}\times \sqrt{A}}$
Distance index of right lung	$P_r$	$\frac{{\sum }_{i=1}^{A_{H,r}}{(d_{r,\mathit{spine}})}_i}{A_{H,r}\times \sqrt{A}}$
Torque index of left lung	$M_l$	$\frac{{\sum }_{i=1}^{A_{H,l}}{(d_{l,\mathit{spine}})}_i·T_i}{A_{H,l}\times \sqrt{A}}$
Torque index of right lung	$M_r$	$\frac{{\sum }_{i=1}^{A_{H,r}}{(d_{r,\mathit{spine}})}_i·T_i}{A_{H,r}\times \sqrt{A}}$
H–L y index of left lung	${\mathit{Wy}}_l$	$\frac{{(C_{H,l})}_x-{(C_l)}_x}{\sqrt{A}}$
H–L y index of right lung	${\mathit{Wy}}_r$	$\frac{{(C_{H,r})}_x-{(C_r)}_x}{\sqrt{A}}$
H–L x index of left lung	${\mathit{Wx}}_l$	$\frac{{(C_{H,l})}_y-{(C_l)}_y}{\sqrt{A}}$
H–L x index of right lung	${\mathit{Wx}}_r$	$\frac{{(C_{H,r})}_y-{(C_r)}_y}{\sqrt{A}}$
Maximal spine temperature	${\mathit{Sp}}_{\mathit{max}}$	max temperature of spine
Average spine temperature	${\mathit{Sp}}_{\mathit{avg}}$	average temperature of the spine