Evaluation of breast lesions by contrast enhanced ultrasound: qualitative and quantitative analysis

To evaluate and compare the diagnostic performance of qualitative, quantitative and combined analysis for characterization of breast lesions in contrast enhanced ultrasound (CEUS), with histological results used as the reference standard.

Ninety-one patients with 91 breast lesions BI-RADS 3-5 at US or mammography underwent CEUS. All lesions underwent qualitative and quantitative enhancement evaluation. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic performance of different analytical method for discrimination between benign and malignant breast lesions.

Histopathologic analysis of the 91 lesions revealed 44 benign and 47 malignant. For qualitative analysis, benign and malignant lesions differ significantly in enhancement patterns (p<0.05). Malignant lesions more often showed heterogeneous and centripetal enhancement, whereas benign lesions mainly showed homogeneous and centrifugal enhancement. The detectable rate of peripheral radial or penetrating vessels was significantly higher in malignant lesions than in benign ones (p<0.001). For quantitative analysis, malignant lesions showed significantly higher (p=0.031) and faster enhancement (p=0.025) than benign ones, and its time to peak was significantly shorter (p=0.002). The areas under the ROC curve for qualitative, quantitative and combined analysis were 0.910 (A(z1)), 0.768 (A(z2)) and 0.926(A(z3)) respectively. The values of A(z1) and A(z3) were significantly higher than that for A(z2) (p=0.024 and p=0.008, respectively). But there was no significant difference between the values of A(z1) and A(z3) (p=0.625).

The diagnostic performance of qualitative and combined analysis was significantly higher than that for quantitative analysis. Although quantitative analysis has the potential to differentiate benign from malignant lesions, it has not yet improved the final diagnostic accuracy.