The Modern Mammogram: Understanding 3D Mammography

Jing S. Chen, MD, is a board-certified radiologist with fellowship training in breast imaging. A member of the Fairfax Radiological Consultants, Dr. Chen is section chief for Breast Imaging at Inova Loudoun Hospital. Read Dr. Chen’s profile.

There have been many advances in breast imaging over the past decade. Digital mammograms have mostly replaced older, film-based images. More recently, 3D mammograms – also known as tomosynthesis – have been introduced into clinical practice.

You may have heard of this new technology from your friends or doctor. In fact, your screening technician may have already asked if you’d prefer a 3D or 2D mammogram. So what’s the difference, and which should you choose? Here’s what you need to know to make an informed decision.

2D vs. 3D Mammography: What’s the Difference?

A routine 2D mammogram study takes two views of each breast: One from top-to-bottom and one from side-to-side. Each single image includes a view of the entire breast. As a result, overlapping tissue on a 2D image can sometimes obscure suspicious tissue, or make an area of benign tissue appear suspicious. Those unclear results can lead to further testing, such as additional mammograms or ultrasound evaluation.

In contrast, a 3D mammogram study produces multiple images per view. The X-ray tube moves around the breast creating cross-sectional images, each just 1 millimeter thick. This technique allows the radiologist to evaluate the breast tissue one layer at a time. Some radiologists describe the study as if they were “flipping through pages of a book.” 3D mammograms can improve accuracy and make it easier to find evidence of breast cancer.

Do Studies Show a Benefit to 3D Mammograms?

Numerous studies have shown that radiologists find approximately 30 to 50% more cancers using 3D mammograms. In addition, this new technology can reduce the number of false positive readings, which can reduce the need for follow-up testing and lower patient anxiety.

How Do Radiation Levels Compare?

At Inova Loudoun Hospital, we use a method known as C-View, which uses 3D images to reconstruct a 2D image for the radiologist to evaluate. With this low-dose technique, the radiation exposure for a 3D mammogram is similar to that of a traditional 2D mammogram.

Are 3D Mammograms More Painful?

Most patients experience little to no difference in discomfort levels between the 2D mammogram or the 3D version. Both procedures compress the breast, and the amount of compression and the time it takes to complete the exam are about the same.

Which Test Should I Choose?

The current research suggests that 3D mammography is a more effective screening tool for detecting breast cancer. However, 2D mammograms are still very common and are also reliable for detecting cancer. If your insurance plan doesn’t cover 3D mammography, you might have greater out-of-pocket costs for the test. It’s important to discuss your options with your doctor and your insurance carrier to determine the best option for you.

Learn more about Inova radiology and diagnostic imaging services.