Quantra™ should be considered a tool for two-grade scale mammographic breast density classification

Objective: To assess the agreement between Quantra™ (Hologic Inc., Bedford, MA) and Breast Imaging Reporting and Data Systems (BI-RADS) and the performance of Quantra at reproducing BI-RADS mammographic breast density (MBD) assessment. Methods: MBD assessment was performed using Quantra and BI-RADS. BI-RADS assessment was performed in two phases (1314 and 292 cases, respectively). Kappa was used to assess the interreader agreement and the agreement between Quantra and BI-RADS, and receiver-operating characteristics analysis was used to assess the performance of Quantra at reproducing BI-RADS rating. Results: Agreement (weighted kappa) between BI-RADS and Quantra in Phase 1 was 0.75 [95% confidence interval (CI): 0.73-0.78] and 0.85 (95% CI: 0.80-0.90) on four-and two-grade scales, respectively. The corresponding agreement in Phase 2 was 0.79 (95% CI: 0.75-0.84) and 0.84 (95% CI: 0.79-0.87) using the majority report. In Phase 1, Quantra demonstrated 93.2% sensitivity and 86.1% specificity for BI-RADS on a two-grade scale (1-2 vs 3-4). In Phase 2, it demonstrated 91.3% sensitivity and 83.6% specificity on a two-grade scale. Conclusion: Quantra is limited in reproducing BI-RADS rating on a four-grade scale; however, it highly reproduces BI-RADS assessment on a two-grade scale.