Breast elastography techniques break new ground

Two new ultrasound elastography techniques show promise for the diagnosis and characterization of breast lesions, according to researchers from France and Korea. They could complement standard gray-scale sonography, evaluate suspicious microcalcifications detected with conventional mammography, and do away with unnecessary, painful needle biopsies.

Dr. Alexandra Athanasiu from the Institut Curie in Paris released preliminary results of "supersonic shear wave" sonoelastography for the characterization of breast lesions at the ECR in Vienna Friday. The technique combines the "palpation" effect of the ultrasound beam with a fast imaging sequence that produces a quantitative measurement of tissue elasticity in real time. It can be done with a conventional probe and is easily reproducible and operator-independent, according to Athanasiu.

Athanasiu and colleagues prospectively assessed 36 nodules from 34 consecutive patients that were correlated with pathology results. They found supersonic shear wave imaging detected all suspicious lesions, including small isoechoic ones, and could reliably characterize benign from malignant nodules. The elasticity values of malignant lesions proved significantly different from benign ones (170 kPa versus 62 kPa, respectively). The technique also characterized correctly the cystic component of simple or complicated cysts detected by B-mode sonography.

"Supersonic shear wave sonoelastography is an innovative operator-independent technique insensible to patient movements that could be a valuable complementary tool for characterizing benign versus malignant lesions," Athanasiu said. "It can avoid unnecessary short-term follow-ups and fine-needle aspiration biopsies."

In the other study, researchers from Seoul led by Drs. Woo Kyung Moon and Nariya Cho used elastography to evaluate the difference in tissue strain associated with benign and malignant microcalcifications detected at screening mammography. They enrolled 50 consecutive women scheduled to undergo ultrasound-guided biopsies. The researchers found that breast lesions associated with malignant microcalcifications tend to demonstrate less strain than benign microcalcifications.

Two experienced radiologists blinded to mammographic and pathology findings interpreted the real-time elastograms of 50 lesions (25 ductal carcinoma in situ and 25 fibrocystic changes) and provided elasticity scores of 1 to 5 according to the degree of strain induced by light compression. Malignant lesions had a mean score of 3, while benign ones scored an average of 1.3. The difference was statistically significant (p<0.001).

"Ultrasound elastography has the potential to improve the accuracy of gray-scale sonography for the detection and differentiation of breast lesions associated with suspicious microcalcifications detected with screening mammography," Moon said.