Mammograms are already one of the most important tools in the fight against breast cancer.
About 40 million of them are performed in the U.S. each year, detecting between 80 and 90 percent of all breast cancers.
Now, there is a new advance. A woman in Boston became the first American to have a mammogram using 3D technology on Monday.
Doctors say the new test opens doors for better diagnoses.
Right now the technology is approved by the FDA but not yet recommended by major cancer groups or women's cancer groups.