The BI-RADS classification of MC differs for FFDM and DBT in 11/107 cases DBT assigned lower BI-RADS classes compared to FFDM in 11 clusters In 4/107 DBT may have missed some malignant and high-risk lesions In 7/107 the ` underclassification ' on DBT was correct , potentially avoiding unnecessary biopsies DBT may miss a small proportion of malignant lesions .