A Better Scan for Breast Cancer
A new technique, digital breast tomosynthesis, improves upon standard mammography.
Scan courtesy of Daniel Kopans
In standard mammography, the X-ray tube, from which the radiation is directed, remains stationary while the X-rays pass through the breast to produce an image that essentially shows all the layers of tissue superimposed one atop another, allowing a tumor to hide in a forest of normal tissue. In a new technique called digital breast tomosynthesis, the tube moves in an arc over the breast, taking multiple images at different angles, which a computer then uses to synthesize all the planes from one side of the breast to the other. “This process eliminates the superimposition of normal tissues, making it easier to see cancers,” says Daniel B. Kopans, senior radiologist in MGH’s breast imaging division and inventor of the technique, which was further developed by Elizabeth Rafferty, director of breast imaging at MGH’s Avon Comprehensive Breast Center. “A conventional mammogram is like a book with clear pages,” Kopans says. “You can hold it up and see all the words on every page, but they are on top of each other, making it difficult to read. DBT allows the radiologist to look at one page at a time, helping detect cancer more easily and producing fewer false positives that lead to unnecessary procedures—and a lot of unnecessary anxiety.”