Comparison of positive predictive values of categorization of suspicious calcifications using the 4th and 5th editions of BI-RADS

OBJECTIVE. The objective of this study was to evaluate changes in the positive predictive value (PPV) of categorization of suspicious calcification for malignancy with the 4th versus the 5th edition of BI-RADS. MATERIALS AND METHODS. A total of 469 cases from 444 women (mean age, 50.1 years; age range, 23-82 years) with pathologically confirmed suspicious calcifications from January 2012 to June 2016 were enrolled in this retrospective study. Two radiologists determined morphology and distribution by consensus and categorized suspicious calcifications using the categorization systems in the 4th and 5th editions of BI-RADS. The PPVs for morphology, distribution, and categorization of calcifications were analyzed. The Pearson chi-square test was used to compare PPVs for morphology and distribution of suspicious calcification. RESULTS. The PPVs of categorization using the 5th edition matched better with BI-RADS category assessment than did categorization using the 4th edition. The PPVs of morphology were as follows: amorphous, 15.9%; coarse heterogeneous, 31.7%; fine pleomorphic, 58.2%; and fine linear or branching, 90.6% (p < 0.001). The PPVs of distribution were as follows: regional, 31.5%; grouped, 31.3%; linear, 50%; and segmental, 77.9% (p < 0.001). When distribution was divided into two types (grouped or regional vs segmental or linear) and analyzed in combination with suspicious morphology, distribution affected the PPVs and categorization of coarse heterogeneous, fine pleomorphic, and fine linear or branching calcifications. CONCLUSION. Categorization using both morphology and distribution according to the BI-RADS 5th edition was helpful to stratify risk levels of areas of suspicious calcification.