Parallel artery and vein: sign of benign nature of breast masses.

OBJECTIVE. The purpose of this study was to assess the parallel artery and vein sign at color Doppler breast ultrasound as a predictor of the benign nature of breast masses. SUBJECTS AND METHODS. A prospective study was performed to identify evidence of a parallel artery and vein in breast lesions consecutively biopsied with a 14-gauge needle under ultrasound guidance. Sensitivity, specificity, positive and negative predictive values, likelihood ratios, and 95% CIs for the parallel artery and vein sign were calculated. RESULTS. The parallel artery and vein sign was identified in 142 of the 1074 masses (13.2%). The specificity for benignity was 99.3% (CI 95%, 98.3–100.0%); sensitivity, 17.6% (CI 95%, 15.0–20.3%); positive predictive value, 99.0% (CI 95%, 96.7–100); negative predictive value, 30.0% (CI 95%, 27.0–32.9); positive likelihood ratio, 24.7 (CI 95%, 21.2–28.7); and negative likelihood ratio, 0.83 (CI 95%, 0.80–0.86). Among masses found to have the parallel artery and vein sign, all BI-RADS ultraso...