MRI technique lowers false positives for breast biopsies

The use of an MRI technique called diffusion-weighted imaging (DWI) could decrease false positive breast cancer findings and prevent unnecessary biopsies, according to a study published online in the journal Radiology.

While dynamic contrast-enhanced MRI is a useful tool in detecting and staging breast cancer, it has been associated with a "substantial" number of false positives that could lead to unnecessary biopsies, according to a release accompanying the study.

"Many benign lesions demonstrate enhancement on DCE-MRI," Savannah C. Partridge, Ph.D., research associate professor at the University of Washington, Seattle Cancer Care Alliance, and the study's lead author, said in the release. "We need another means for differentiating benign lesions from malignancies."

One possible solution the researcher's identified is DWI—an MRI technique that calculates the apparent diffusion coefficient (ADC), which is a measure of how water moves through tissue.

In the study, researchers evaluated the DWI characteristics of  175 nonmalignant breast cancers in 165 women. Based on ADC values that were greater than a predetermined diagnostic threshold, the researchers used DWI to successfully characterize as benign 46 percent of the lesions that had been identified as false-positive findings on DCE-MRI.

"We were excited to see the number of false positives that could be reduced through this approach," Partridge said. "DWI gives us extra microstructural information to distinguish among lesions. We can use ADC values to draw a cutoff above which we might not need to do a biopsy."

For more:
- read the abstract
- check out the announcement