Interreader Agreement and Diagnostic Confidence in Discriminating Masses and Nonmass Lesions at Breast US

> .99) was comparable between the definite and controversial NML groups. Conclusion Interreader agreement for classifying lesions at US as masses or NMLs was moderate to substantial, with high concordances rates. Smaller lesions or subtle architectural distortions were less likely to be consistently classified as NMLs, whereas lesions with echogenic foci associated with calcifications at mammography and microcysts were more likely to be consistently classified as NMLs. © RSNA, 2025 See also the editorial by Hooley in this issue.