What is breast density?

Breasts are made up of a mixture of fibrous and glandular tissue and fatty tissue. Your breasts are considered dense if you have a lot of fibrous or glandular tissue but not much fat. Density may decrease with age in some women as changes occur over their lifespan.

How do you know if you have dense breasts?

Breast density is determined by the radiologist who reads your mammogram. There are four categories of mammographic density. The radiologist assigns each mammogram to one of these categories.

The radiologist will report your breast density in the mammography report sent to your referring doctor. Some radiology practices, including Atlantic Medical Imaging, also provide this information to you along with the results of your mammogram.

Radiologists classify breast density using a 4-level density scale:
1. Almost entirely fatty
2. Scattered areas of fibroglandular density
3. Heterogeneously dense
4. Extremely dense


Why is it important to know if you have dense breasts?

Having dense breasts slightly increases your overall risk of getting breast cancer. Dense breasts also make it more difficult for doctors to spot cancer on mammograms. Dense tissue appears white on a mammogram. Lumps, both benign and cancerous, also appear white. So, mammograms can be less accurate in women with dense breasts.

What should I do if I have dense breasts?
Are there other tests, better than mammography,
for dense breasts?

In dense breasts, cancer can be hard to see on a mammogram. Magnetic resonance imaging (MRI), and to a lesser extent ultrasound, can find breast cancers that can’t be seen on a mammogram. However, MRI and ultrasound may show findings that are not cancer, which can result in added testing and unnecessary biopsies.

After consultation with your doctor, additional screening tests such as breast MRI and screening breast ultrasound, in addition to your annual mammogram, may be appropriate.

What about other breast cancer risk factors?

Whether your breasts are dense or not, other factors may still place you at increased risk for breast cancer, including a family history of the disease, previous chest radiation treatment for cancer and previous breast biopsies that show you are at high risk.

At Atlantic Medical Imaging, we perform a comprehensive breast cancer risk analysis on all mammography patients and report the results to your doctor.

If you are in the highest risk category we will notify you directly and may recommend a breast MRI. Talk to your doctor, discuss your history and what additional exams may be right for you.

Even if you are at low risk, and have entirely fatty breasts, you should still get an annual mammogram starting at age 40.

© Atlantic Medical Imaging