Table 4.

Performances achieved by U-net${}_2$ in COVID-19 lesion segmentation, evaluated in terms of the vDSC

U-net	Trained on	Test set	U-net size	Original CT size
			(vDSC)	(vDSC)
U-net${}_2^{60\%}$	COVID-19 challenge	COVID-19 challenge	0.51 ± 0.24	0.51 ± 0.25
	COVID-19 Challenge	MosMed	0.39 ± 0.19	0.40 ± 0.19
	MosMed	MosMed	0.54 ± 0.22	0.55 ± 0.22
	MosMed	COVID-19 challenge	0.25 ± 0.23	0.25 ± 0.23
	COVID-19 challenge	COVID-19 challenge	0.49 ± 0.21	0.50 ± 0.21
	+ MosMed	+ MosMed
U-net${}_2^{90\%}$	COVID-19 challenge	COVID-19 challenge	0.64 ± 0.23	0.65 ± 0.23
	+ MosMed	+ MosMed

The composition of the train and test sets is reported in Table 2