Fig. 1

Pattern of mammographic density and corresponding sample sizes. Categories of mammographic density based on parenchymal pattern (PP) and BI-RADS density. Panels from left to right display representative examples of low MBD (PP category N1 [N = 60] and BI-RADS category “fatty” [N = 9]; moderate MBD (PP categories P1 [N = 32] or P2 [N = 59], and BI-RADS categories “scattered” [N = 55]or “heterogeneously dense” [N = 85]); and high MBD (PP category DY [N = 131] and BI-RADS category “extremely dense” [N = 39])