Clinical value of relative quantification ultrasound elastography in characterizing breast tumors

To evaluate ultrasound elastography (USE) using strain ratio (SR), a relative quantification approach for breast lesions characterization.

One hundred forty-seven consecutive patients with a total of 156 breast lesions underwent USE. Technical accuracy was assessed automatically. For SR evaluation a rounded ROI was depicted inside fat (F), glandular tissue (G) and inside the lesion (L), preferably at the same depth. R1, mean value of the G and F ratio, stands for in background tissue composition elasticity. R2; mean value of L/F stands for in lesion elasticity, both evaluated in arbitrary unit (au). Two-years follow-up and pathology results were standard of reference. Mann-Whitney test, ROC analysis and Chi-square with Yates correction were used.

With the exception of 27 cysts, 17 malignant and 112 benign lesions were found. R1 values were 1.6±0.7au and 1.2±0.9au (p=0.015 NS); R2 values were 6.1±2.5au and 1.9±1.3au (p<0.001) for malignant and benign lesions, respectively. A threshold of 3.3au showed a sensitivity and specificity of 88% and 87%, respectively with an AUC of 93%. Fifteen false positive and two false negative were detected.

Relative quantification of ultrasound elastography allows to find high levels of diagnostic accuracy in characterizing breast tumors above all in downgrading BI-RADS 3 and 4 lesions.