Role of Sonoelastography in the Differentiation between Benign and Malignant Breast Lesions

To prospectively evaluate the accuracy of real time elastography (ultrasound strain imaging) for distinguishing between benign and malignant solid breast lesions with the pathologic results as the reference standard. We also evaluated if the fat÷lesion ratio could semiquantitatively evaluate the stiffness of breast lesions.

Conventional ultrasonography (US) and real time elastography were performed in 100 women with breast masses with the mean age is 50 years. Elasticity images were given an elasticity score according to the degree and distribution of the strain induced by light compression with 1-3 is benign and 4-5 is malignant. We also calculated the ratio of the normal breast tissue to that of the lesion (fat÷lesion ratio) of the different breast lesions with the fat as the reference. The cutoff point was 4.8 with ratio below this level is considered benign and above this level is considered malignant.

For elasticity score, the mean standard deviation was 4.1 for malignant lesions and 2.1 for benign lesions (p<0.001). When a cutoff point between 3 and 4 was used, elastography had 87.2% sensitivity, 90.6% specificity and 90% accuracy. The fat÷lesion ratio (F÷L ratio) of the benign lesions was different from that of the malignant ones.

US strain imaging can facilitate improved classification of benign and malignant breast masses and has the potential to aid their diagnosis. By using the F÷L ratio, the stiffness of breast lesions could be semiquantitated and this method may provide another diagnostic method in addition to the scoring system.

Breast - Sonoelastography - Strain imaging - Fat-lesion ratio.