Table 2.

The definitions of evaluation metrics.

Metrics	Mathematical definition	Meaning	Range
Dice similarity coefficient (DSC)	$DSC(A,B)=\frac{2|A\cap B|}{\left|A\right|+\left|B\right|}$	Overlap between the two contours	0–1
Jaccard index (JI)	$JI(A,B)=\frac{|A\cap B|}{|A\cup B|}$	Similarity of the two contours	0–1
Average surface distance (ASD)	$ASD=\frac{{\overrightarrow{d}}_{H,avg}(A,B)+{\overrightarrow{d}}_{H,avg}(B,A)}{2}$ ${\overrightarrow{d}}_{H,avg}(A,B)=\frac{1}{\left|A\right|}{\sum }_{a\in \left|A\right|}{min}_{b\in \left|B\right|}d(a,b)$	Average surface distance between two contours (mm)	≥0
Hausdorff distance (HD)	H(A, B) = max(h(A, B), h(B, A)) $h(A,B)=\underset{a\in A}{max}(\underset{b\in B}{min}\left|\right|a-b\left|\right|)$	Maximum surface distance between two contours (mm)	≥0