Digital breast tomosynthesis (3-D mammography), available at Duke locations in Durham and Raleigh, is the latest diagnostic advance in breast cancer detection. Jay Baker, MD, a Duke radiologist, explains what it is, and how 3-D mammography differs from traditional digital mammography.
What Is Digital Breast Tomosynthesis?
Breast tomosynthesis takes several X-rays, which are put together to form a 3-D image of the breast.
The actual procedure is not much different from a traditional mammogram. In fact, we use similar equipment, and it requires the same breast compression. The difference is in how we take the X-rays. During compression, a camera moves over the breast and takes multiple very low-dose images. The camera then comes back to the midline of the breast and takes a regular mammogram image. The compression is then released. The entire process takes about seven seconds per compression, only slightly longer than before.
Why Is a 3-D Mammogram Better?
Creating a 3-D image of the breast allows us to identify a breast cancer that may be hidden on regular mammography. Current mammography creates a single, 2-dimensional image. Tissue at the top, the middle, and the bottom of the breast all overlap onto this one image. 3-D mammography creates a series of imaging slices at different levels of the breast. This allows us to view each slice and detect breast cancer that can be hidden when the tissue overlaps on a 2-D image.
What Are the Benefits of a 3-D Mammogram?
We can often see breast cancer far more clearly with tomosynthesis than we can with regular digital mammography. Several large studies confirm that tomosynthesis is 40 percent better at detecting breast cancer than traditional digital mammography. At the same time, it results in up to 30 percent fewer unnecessary callbacks. This means fewer people are asked to return for additional testing. It’s one of those rare win-wins. Usually when you find more cancer, you find more benign things also. That can cause a lot of anxiety and concern that we can now avoid.
Who Should Get 3-D Mammography?
All women who need screening mammograms will benefit from 3-D mammograms. That is when we are looking to see if breast cancer is present in a woman who has no symptoms of breast cancer. It is particularly useful in women who have denser breast tissue which is more difficult to read on traditional mammography.