Cobb Angle Measurement of Spine from X-Ray Images Using Convolutional Neural Network

Table 2

Dice similarity coefficient (DSC) from 5-fold cross-validation of U-Net, Residual U-Net, and Dense U-Net.

k-fold	Dice similarity coefficient (DSC)
	U-Net	Residual U-Net	Dense U-Net
k = 1	0.940 ± 0.036	0.952 ± 0.023	0.947 ± 0.028
k = 2	0.942 ± 0.032	0.951 ± 0.029	0.947 ± 0.029
k = 3	0.942 ± 0.033	0.952 ± 0.025	0.949 ± 0.028
k = 4	0.941 ± 0.034	0.949 ± 0.030	0.947 ± 0.026
k = 5	0.942 ± 0.035	0.952 ± 0.028	0.947 ± 0.030
Average ± std.	0.941 ± 0.034	0.951 ± 0.027	0.948 ± 0.028
Parameter size	1.21 million	1.19 million	1.20 million
Training time	0.34 hour	0.77 hour	2.33 hour
Testing time (each image)	0.03 second	0.05 second	0.07 second