Table 1.

Intra-observer agreement values for BI-RADS US descriptors. The term “overall” represents agreement in all the features together. O1, O2, and O3 refer to first, second and third observations respectively.

Feature	O1 vs. O2 (1 month interval) (κ)	O2 vs. O3 (2 months interval) (κ)	O3 vs. O1 (3 months interval) (κ)	Intra-observer (κ) [15]	Intra-observer (κ) [16]
Shape	0.51	0.75	0.46	0.71	0.73
Orientation	0.65	0.71	0.56	0.83	0.68
Boundary	0.16	0.53	0.15	0.85	0.68
Echo pattern	0.98	0.70	0.69	0.67	0.65
Posterior acoustic features	0.98	0.69	0.67	0.82	0.64
Margin	0.95	0.56	0.56	0.59	0.64
Overall	0.77 (Substantial)	0.66 (Substantial)	0.56 (Moderate)	0.77 (Substantial)	0.74 (Substantial)