Novel approach in the evaluation of ultrasound BI-RADS 3 & 4 breast masses with a combination method of elastography & Doppler

BACKGROUND & OBJECTIVES: Ultrasound BI-RADS categories 3 and 4 constitute those breast masses which cannot be confidently classified as benign or malignant, owing to their morphological characteristics. These masses are further managed by follow up and biopsy, respectively. This study aims to evaluate the role of strain elastography and Doppler in better characterization of these sonographically indeterminate breast masses as benign or malignant. METHODS: Fifty female patients with ultrasound BI-RADS 3 or 4 were evaluated with strain elastography and color Doppler including spectral analysis. Eight variables were assessed by elastography and Doppler, including a new phenomenon called bidirectional arterial flow (BAF). The findings were correlated with the gold standard diagnostic method of histopathology/cytology. Based on findings of combined elastography and Doppler method, the initial ultrasound BI-RADS categories of masses were re-categorized by up-gradation or down-gradation. Sensitivity, specificity, accuracy, positive predictive value, negative predictive value and receiver operating characteristic (ROC) curves were used to estimate the diagnostic performance of the combination method. RESULTS: Using ROC analysis, the positivity of ≥3 among the total eight variables correlated with malignancy on histopathology. Sensitivity, specificity and accuracy of the combination method using cut-off score ≥3 (i.e. at least three out of the eight parameters in the combination method being positive) for the prediction of malignancy was 100, 76.47 and 92 per cent, respectively, with the area under curve being 0.967. In addition, BAF was found predictive of malignancy with a diagnostic accuracy of 70 per cent. INTERPRETATION & CONCLUSIONS: This non-invasive, cheaper and readily accessible combination method of strain elastography and Doppler imaging can improve the diagnostic characterization of sonographically indeterminate breast masses and may obviate the need of magnetic resonance imaging and unnecessary biopsies, thus proving helpful in resource-poor countries.