Table 2.

Inter-observer analysis, showing the ICC values and the number of stable features per feature group, defined as high (ICC ≥ 0.8), median (0.8 > ICC ≤ 0.5), and low (ICC < 0.5) stability.

N-0	Stability class	N	ICC	ICC (95 % CI)
1	First order statistics
	High stability	8	0.810	0.795–0.823
	Medium stability	8	0.510	0.478–0.540
	Low stability	1	0.330	0.292–0.366
2	Gray Level Co-occurrence Matrix (GLCM)
	High stability	3	0.820	0.805–0.833
	Medium stability	13	0.500	0.468–0.530
	Low stability	6	0.240	0.200–0.278
3	Gray Level Run Length Matrix (GLRLM)
	High stability	1	0.810	0.795–0.823
	Medium stability	7	0.52	0.488–0.549
	Low stability	8	0.240	0.200–0.278
4	Gray Level Size Zone Matrix (GLSZM)
	High stability	5	0.810	0.795–0.823
	Medium stability	7	0.54	0.509–0.568
	Low stability	4	0.24	0.200–0.278
5	Gray Level Dependence Matrix (GLDM)
	High stability	2	0.820	0.805–0.833
	Medium stability	6	0.680	0.656–0.701
	Low stability	6	0.240	0.200–0.278
6	Neighbouring Gray Tone Difference Matrix (NGTDM)
	High stability	1	0.800	0.784–0.814
	Medium stability	4	0.500	0.468–0.530
	Low stability	–	–	–