To evaluate the values of RF time-series signal based on ultrasonic radio-frequency flow in the differentiation of benign and malignant breast lesions.

A commercially available clinical ultrasound scanner, Sonix TOUCH (Ultrasonix Medical Corporation, Richmond, Canada) with a L14–5 linear ultrasound transducer was used to simultaneously collect B-mode images and RF data from breast lesions. The ultrasound probe displaying the maximal plane of the breast lesion was kept in the same position for 10 seconds. The ultrasound RF data from region of interest was imported into software developed by our lab for ultrasound spectral analysis and 9 spectral parameters including SMR fractal dimension, Higuchi fractal dimension, Slope, Intercept, Mid-band fit, S1, S2, S3, S4 were calculated. 137 patients with 137 breast lesions confirmed by pathological or follow-up findings were included in the study. Of the 137 breast lesions, 86 malignant and 30 benign lesions were confirmed by ultrasound guided core needle biopsy or surgical excision, and the rest 21 lesions were presumed benign as no significant change was found after at least 2 years of follow-up.

There are significantly difference in spectral parameters including SMR fractal dimension, Higuchi fractal dimension, Slope, Intercept, Mid-band fit, S1, S2, S3 and S4 between the malignant and benign breast lesions (0.75±0.77 vs 0.82±0.10, t=-4.722, 1.31±0.07 vs 1.42±0.10, t=-7.476, -0.24±0.04 vs -0.26±0.06, t=1.986, 0.19±0.03 vs 0.21±0.048, t=-3.391, 0.067±0.011 vs 0.08±0.019, t=-5.319, 3.22±0.54 vs 3.60±0.83, t=-3.298, 0.53±0.12 vs 0.73±0.23, t=-6.467, 0.31±0.06 vs 0.45±0.13, t=-9.207, 0.24±0.05 vs 0.38±0.12, t=-9.367, all P<0.05).

RF time-series signal based on ultrasonic radio-frequency flow could provide a new imaging method with a simple, low-cost noninvasive technique for the differential diagnosis of the benign and malignant breast lesions.