Table 4.

Number of discrepant cancers and probable reasons for misclassification in digital breast tomosynthesis (DBT) and digital mammography (DM)

Reason for misclassification	Classified as BI-RADS 3, 4 or 5 in DBT and as BI-RADS 1 or 2 in DM (DBT only group)	Classified as BI-RADS 3, 4 or 5 in DM and as BI-RADS 1 or 2 in DBT (DM only group)
Visibility	13 (ILC, n =  6; IDC, n = 6; Tub, n = 1)	0
Radiographic appearance	3 (ILC, n = 1; IDC, n = 2)	1 (IDC)
Interpretative error	3 (ILC, n = 2; intracystic papillary cancer, n = 1)	6 (ILC, n = 3; IDC, n = 1; Tub = 1; ductal carcinoma in situ, n = 1)

BI-RADS, Breast Imaging Reporting and Data System; IDC, invasive ductal carcinoma; ILC, invasive lobular carcinoma; Tub, invasive tubular carcinoma.