Solid breast mass characterisation: use of the sonographic BI-RADS classification

The aim of this study was to assess the reliability of the sonographic Breast Imaging Reporting and Data System (BI-RADS) classification in differentiating benign from malignant breast masses.

A total of 292 female patients with breast masses undergoing biopsy between November 2004 and March 2006 in our department were included in this study. All lesions were classified according to the sonographic BI-RADS lexicon. Sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) for the sonographic BI-RADS lexicon and PPV and NPV for each lesion category and each sonographic descriptor were calculated. The chi(2) test and the Fischer exact test were used to evaluate our results.

Univariate analysis showed a significant difference between malignant and benign groups with regard to morphology (p<0.001), horizontal-vertical diameter ratio<1 (p<0.002), orientation (p<0.001), noncircumscribed margins (p<0.001), echogenic halo (p<0.001), hypoechoic pattern (p=0.035), shadowing (p<0.001) and surrounding tissue alterations (p=0.001). The cumulative risk for malignancy was 64 and 10 times higher, respectively, in categories 5 and 4 than in category 3.

The sonographic BI-RADS lexicon is an important system for describing and classifying breast lesions.