The only screening tool that has been shown to reduce breast cancer death rates in the U.S. is mammograms. There has been a 30 percent decrease in deaths since 1990, Kopans said.
While Berg said that ultrasounds are cheaper and probably more readily available to more women, Kopans said "MRI has an even better chance of saving more lives.
"Ultrasound has shown important potential, but before the population is subjected to ultrasound screening, a randomized control trial should be done to prove its benefit," said Kopans.
Nevertheless, Berg believes there is a place for these supplemental screenings for women at higher risk of developing breast cancer.
"I don't have to be apologetic for overscreening when we found that 94 percent of the cancers found with these tools were invasive cancer, and 96 percent of them had not yet spread to lymph nodes," said Berg. "This is exactly the type of cancer that is appropriate for these screening tools."