Elastography pinpoints need for biopsy
Ultrasound elastography can help differentiate benign from malignant breast lesions in some patients by indicating tissue softness—information that could prevent unnecessary biopsies.
Cancerous tumors are typically harder than surrounding healthy tissue or cysts. Elastography uses ultrasound imaging to measure a lesion's compressibility and mechanical properties. Hiroko Satake, MD, of Nagoya University School of Medicine in Japan, led a team that sought to evaluate the ability of ultrasound elastography as well as the apparent diffusion coefficient (ADC) values using magnetic resonance diffusion-weighted imaging (MR DWI) to predict the malignancy of breast masses.
The team analyzed 115 breast masses that had been recommended for biopsy, 52 of which had been classified as category 4 and 63 as category 5 under the Breast Imaging Reporting and Data System (BI-RADS), based on the combined findings of mammography, B-mode sonography, and dynamic contrast-enhanced MRI.
Overall, ultrasound elastography was 79% accurate in identifying cancer. The elasticity score was predictive of malignancy; the ADC value was not independently predictive. The elasticity score significantly predicted malignancy among the BI-RADS category 4 masses compared with the ADC value, which was found to be a nonsignificant predictor. In the category 5 group, however, neither the elasticity score nor the ADC value significantly predicted malignancy.
“Our results show that elasticity imaging provides relatively reliable predictions for malignancy, especially in BI-RADS category 4 masses, compared with MR DWI,” concluded the authors in American Journal of Roentgenology (2011;196:202-209).
In a separate statement, Dr. Satake recommended that based on his group's findings, patients with BI-RADS 4 masses should undergo biopsy if their ultrasound elasticity score is 4 or 5.