The Dice metric and contour distance metrics between automated segmentation and manual segmentation for short-axis images, as well between segmentations by different human observers

(a) Dice metric
	Auto vs Manual	O1 vs O2	O2 vs O3	O3 vs O1
	(n = 600)	(n = 50)	(n = 50)	(n = 50)
LV cavity	0.94 (0.04)	0.94 (0.04)	0.92 (0.04)	0.93 (0.04)
LV myocardium	0.88 (0.03)	0.88 (0.02)	0.87 (0.03)	0.88 (0.02)
RV cavity	0.90 (0.05)	0.87 (0.06)	0.88 (0.05)	0.89 (0.05)
(b) Mean contour distance (mm)
LV cavity	1.04 (0.35)	1.00 (0.25)	1.30 (0.37)	1.21 (0.48)
LV myocardium	1.14 (0.40)	1.16 (0.34)	1.19 (0.25)	1.21 (0.36)
RV cavity	1.78 (0.70)	2.00 (0.79)	1.78 (0.45)	1.87 (0.74)
(c) Hausdorff distance (mm)
LV cavity	3.16 (0.98)	2.84 (0.70)	3.31 (0.90)	3.25 (0.96)
LV myocardium	3.92 (1.37)	3.70 (1.16)	3.82 (1.07)	3.76 (1.21)
RV cavity	7.25 (2.70)	7.56 (2.51)	7.35 (2.19)	7.14 (2.20)

The first column shows the difference between automated and manual segmentations on a test set of 600 subjects. The second to fourth columns show the inter-observer variability, which is evaluated on a randomly selected set of 50 subjects, each being analysed by three different human observers (O1, O2, O3) independently. The mean and standard deviation (in parenthesis) of the metrics are reported