Accuracy of sonographic findings in breast cancer: correlation between BI-RADS® categories and histological findings* Acurácia dos achados ultrassonográficos do câncer de mama: correlação da classificação BI-RADS® e achados histológicos

OBJECTIVE: The main purpose of the present study is to evaluate the accuracy of ultrasonography (BI-RADS) in the diagnosis of breast cancer whereas the additional specific objectives are to describe the frequency of different sonographic findings and evaluating interobserver agreement. MATERIALS AND METHODS: Images of 110 patients who had been referred for biopsy with previous diagnosis of breast nodules were independently reviewed by two specialists according to the BI-RADS classification. Histological findings were utilized as a gold-standard. The accuracy of findings was determined. The chi-squared test for categorical variables was utilized in the analysis of the differences resulting from the groups comparison, and the interobserver agreement was calculated with kappa (κ) statistics. RESULTS: Among 110 breast masses evaluated by ultrasonography, 76 (69%) were benign and 34 (30.9%) were malignant. According to the radiologists, the sensitivity ranged from 70.5% to 82.3%, negative predictive value, from 81.1% to 87.5%, positive predictive value, from 42.1% to 45.1%, specificity from 56.58% to 55.2%, and accuracy from 60.9% to 63.6%. The global interobserver agreement was considered as moderate (κ = 0.50). CONCLUSION: The fourth edition of BIRADS provides radiologists with an accurate clinical decision support system for the diagnosis and management of breast disease.