Istomin A, Masarwah A, Vanninen R, et al. - This study was sought to ascertain the diagnostic performance of the Kaiser score and to compare it with the breast imaging reporting and data system (BI-RADS)–based multiparametric classification system (MCS). The database of 499 consecutive patients with structural 3.0 T breast MRI and 697 histopathologically verified lesions were separately evaluated by two breast radiologists. Researchers recorded Kaiser scores and corresponding MCS categories. They calculated the sensitivity and specificity of the Kaiser score and the MCS categories to differentiate benign from malignant lesions. They further examined interobserver reproducibility and receiver operating characteristic parameters. It has been reported that the Kaiser score exhibited high diagnostic accuracy with excellent interobserver reproducibility. The data indicated that MCS had perfect sensitivity but low specificity. The outcomes revealed that, although the Kaiser score had slightly lower sensitivity, its specificity was 3–4 times greater than that of the MCS. Therefore, the Kaiser score has the potential to considerably decrease the biopsy rate for true negative lesions.