Articles
Dense breast tissue: What it means to have dense breasts
How does dense breast tissue affect breast cancer screening?
Content
What is dense breast tissue?
How do doctors determine if you have dense breast tissue?
What causes dense breast tissue?
Why does breast density matter?
What tests are recommended for breast cancer screening?
Are other tests more effective?
How do doctors determine if you have dense breast tissue?
The radiologist who analyzes your mammogram determines the ratio of nondense tissue to dense tissue and assigns a level of breast density.
Levels of density are described using a results reporting system called Breast Imaging Reporting and Data System (BI-RADS). The levels of density are often recorded in your mammogram report using letters. The levels of density are:
- A: Almost entirely fatty indicates that the breasts are almost entirely composed of fat. About 1 in 10 women has this result.
- B: Scattered areas of fibroglandular density indicates there are some scattered areas of density, but the majority of the breast tissue is nondense. About 4 in 10 women have this result.
- C: Heterogeneously dense indicates that there are some areas of nondense tissue, but that the majority of the breast tissue is dense. About 4 in 10 women have this result.
- D: Extremely dense indicates that nearly all of the breast tissue is dense. About 1 in 10 women has this result.
In general, women with breasts that are classified as heterogeneously dense or extremely dense are considered to have dense breasts. About half of women undergoing mammograms have dense breasts.
