What is a mammogram?

Mammography is an X-ray examination which uses extremely low doses of radiation to obtain accurate images of the breasts. It is the best way of detecting small cancers even before they can be felt. The American Cancer Society estimates that one in eight women will develop breast cancer in her lifetime. While the exact cause of breast cancer has not been found, we do know that it is treatable and can often be cured when detected early. Mammography, physician examination and breast self examination are the three components of a complete screening program for early breast cancer detection.

Breast cancer is the most diagnosed cancer in women, affecting one in every eight women in the U.S. The goal of screening exams is to identify breast abnormalities as early as possible, facilitate early cancer detection, and thereby provide patients with more treatment options and a better chance for survival. Yearly mammography will help detect subtle new findings. Women whose breast cancer is detected at an early stage have a 93% or better survival rate in the first five years.

3D mammography, sometimes referred to as tomosynthesis, takes only a few moments longer than a standard mammogram. In both instances, the breast is compressed between plates to obtain images. However, during a 3D mammogram, the scan takes a series of X-rays from different angles. The computer then digitally recreates the breast, and radiologists can view a series of “slices” of the image, making it easier to see and evaluate possible abnormalities.

Women with dense breast tissue benefit most. Breasts are made up of several tissues, including glandular tissue, connective tissue, and fatty tissue. “Dense breast tissue” means a woman has more glandular and connective tissue than fatty tissue. This is important because on a standard mammogram, glandular/connective tissue and cancer both appear white, making it hard to differentiate between the two. 

The ratio of glandular/connective tissue to fatty tissue varies widely among women. Breast density only describes how breasts look on a mammogram. It isn’t a measure of how they feel. Clinically speaking, breast density is gauged on a scale of one to four, from almost entirely glandular/connective tissue to almost entirely fatty tissue, or degrees in between. Eighty percent of women are not on either end of the spectrum but somewhere in the middle. However, younger women and women with smaller breasts are more likely to have dense breasts. For many, breasts become less dense after menopause.

On the results letter you receive following a mammogram, it should tell you if you have dense breasts. If you find that you do, you should talk to your doctor about alternative testing. That may be 3D mammography. It may also be an ultrasound or an MRI, depending on your family history and just how dense your breasts are. 

Many studies in Europe and the U.S. have substantiated superior breast cancer detection rates when combining 3D mammography with conventional 2D mammography. This ability to detect breast cancer at an earlier stage saves lives.

If you think you’d benefit from a 3D mammogram, talk to your doctor for a referral to one of Dignity Health Advanced Imaging locations.