Sonographic differentiation of benign from malignant breast lesions: value of indirect measurement of ultrasound velocity.

OBJECTIVE

The purpose of this study was to test the value of indirect measurements of ultrasound velocity in the sonographic differentiation of benign from malignant breast lesions.

SUBJECTS AND METHODS

One hundred six mammographically examined preoperative patients with 54 benign and 70 malignant histopathologically proven lesions were examined as follows. The compressed breast was completely penetrated by an ultrasound beam from a 7.5-MHz linear transducer. A stainless steel plate underneath the breast appeared on sonograms of normal breast tissue as a hyperechoic line. Some lesions caused changes in the attenuation and velocity of the ultrasound beam, which in turn caused the hyperechoic line representing the steel plate below those lesions on sonograms to appear elevated and changed in echogenicity. By measuring elevation, if any, and the corresponding length of lesions on the sonogram, we studied the results of this sonographic examination and compared them with mammographic findings.

RESULTS

Sixty of the 70 cancers caused the hyperechoic line representing the steel plate on sonograms to appear elevated and changed in echogenicity at points below those lesions. Twenty-five of the 54 benign lesions also showed this effect, but the amount of elevation seen on sonograms was smaller with 14 of these 25 lesions than with 57 of the 60 malignant lesions. The new method complements mammographic findings by true definition of mammographically false-negative cancers and false-positive benign lesions. Accuracy was improved by use of both mammography and sonography in comparison with that obtained with mammography alone (85% versus 73%).

CONCLUSION

Indirect measurement of relative ultrasound velocity can help differentiate benign from malignant breast lesions. The systematic use of mammography and this new sonographic method might improve the detection of cancers and help avoid biopsies of benign lesions.