Distinguishing Benign from Malignant Masses at Breast US: Combined US Elastography and Color Doppler US-Influence on Radiologist Accuracy

Purpose: To investigate the effect of the combined use of ultrasonographic (US) elastography and color Doppler US on the accuracy of radiologists in distinguishing benign from malignant nonpalpable breast masses and in making the decision for biopsy recommendations at B-mode US. Materials and Methods: This prospective study was conducted with institutional review board approval; written informed consent was obtained. A cohort of 367 biopsy-proved cases in 319 women (age range, 22-78 years; mean age, 48.6 years) with B-mode US, US elastographic, and Doppler US images was included. Five blinded readers independently scored the likelihood of malignancy for four data sets (ie, B-mode US alone, B-mode US and elastography, B-mode US and Doppler US, and B-mode US, US elastography, and Doppler US). The area under the receiver operating characteristic curve (A(z)) values, sensitivities, and specificities of each data set were compared. Results: The A(z) of B-mode US, US elastography, and Doppler US (average, 0.844; range, 0.797-0.876) was greater than that of B-mode US alone (average, 0.771; range, 0.738-0.798) for all readers (P = .001 for readers 1, 2, and 3; P < .001 for reader 4; P = .002 for reader 5). When both elastography and Doppler scores were negative, leading to strict downgrading, the specificity increased for all readers from an average of 25.3% (75.4 of 298; range, 6.4%-40.9%) to 34.0% (101.2 of 298; range, 26.5%-48.7%) (P < .001 for readers 1, 2, 4, and 5; P = .016 for reader 3) without a significant change in sensitivity. Conclusion: Combined use of US elastography and color Doppler US increases both the accuracy in distinguishing benign from malignant masses and the specificity in decision-making for biopsy recommendation at B-mode US. (C) RSNA, 2011