3D vs. 2D Mammograms: What You Need to Know

Up until about two decades ago, all mammograms were done using an X-ray machine, which generated two-dimensional (2D) images of breast tissue.

In 2011, however, the U.S. Food and Drug Administration (FDA) approved the use of the first 3D mammogram device. It takes multiple detailed images of the breast, allowing radiologists to evaluate breast tissue layer by layer. It also offers more precise imaging than 2D machines.

Both types of machines are still used to screen for breast cancer , and mammography of all kinds is still widely considered to be the gold standard for screening.

Here's what you need to know about both types.

What Is a 3D Mammogram?

3D mammography, also called digital breast tomosynthesis, is a newer form of digital X-ray mammography that uses small doses of radiation and creates 3D images of breast tissue. Many healthcare facilities still use 2D mammography devices, but 3D mammography has increasingly become a standard technique for diagnosing breast cancer.

"More than half of mammograms performed in the U.S. now are 3D, and its use is increasing," says John Lewin, MD , the chief of the breast imaging division at Smilow Cancer Hospital and Yale Cancer Center in New Haven, Connecticut.

3D vs. 2D Mammogram: What's the Difference?

The main difference between 2D and 3D mammograms lies in the images. While the former produces two-dimensional images of the breast, the latter produces clearer, three-dimensional images.

In both cases, the aim of the mammogram is to detect calcifications, masses, and other suspicious-looking tissue that could signal cancer. Research does suggest that 3D mammograms are more accurate than 2D mammograms and have a lower rate of false positives (when a test falsely registers a cancer), according to a study published in 2023.

Who Should Get a 3D Mammogram?

2D mammograms are still useful for screening and diagnosis. If your doctor doesn't recommend a 3D mammogram for you, it most likely means 2D mammography suffices to screen you.

3D mammograms may be best in some cases, such as for people who are considered at higher risk for breast cancer or who have dense breast tissue . Cancerous tumors look similar to dense tissue on 2D mammograms.

Indeed, research suggests that the sensitivity of 2D mammography in breast cancer detection for people with dense breast tissue drops from 85 percent to between 48 and 64 percent. In this case, a 3D mammogram may be recommended, or a 2D mammogram in conjunction with an ultrasound , which uses sound waves to generate images of breast tissue.

What to Expect During a Mammogram

The experience of a 3D mammogram is very similar to a standard 2D mammogram, says Claudia Cotes, MD , an assistant professor and breast cancer radiologist at UTHealth Houston.

During both procedures, you will be required to undress above your waist and will be given a wrap to wear. The radiographer or technician will ask you to stand in front of the mammogram machine, then lower a plate-like structure on the machine to compress your breast for about 10 to 15 seconds.

During a 2D digital mammogram, the radiographer takes a picture from the sides and another from above each breast. During a 3D mammography, the X-ray device is positioned to move in an arc around the breast, taking multiple low-dose X-ray images.

While the procedure may differ slightly, 3D and 2D mammograms take about 20 minutes.

Getting Your 3D Mammogram Result

Results from a 3D mammogram are usually available within a few days, sometimes even the same day, says Dr. Cotes. The turnaround time may vary depending on the facility and workload, but patients are typically notified promptly once the results are ready.

If your screening mammogram shows abnormal results, your medical center will call you back in for more imaging, Dr. Lewin says. When called back, additional mammographic images, ultrasound, or both will be performed to determine if a biopsy is necessary.

An abnormal mammogram result does not always mean a person has breast cancer. Sometimes, mammograms pick up issues like cysts and benign growths.

Is 3D Mammography Safe?

Sometimes 3D mammograms are used on their own, and sometimes in conjunction with 2D imaging. One concern about any kind of mammogram is radiation exposure. The exposure from 3D mammograms can range from slightly lower to slightly higher than that from standard 2D mammograms.

Health experts believe the benefits outweigh any possible harm from the small amount of radiation exposure. Also, recent 3D mammography devices come with technology and software that reduce radiation exposure and make it possible to generate synthetic 2D images, eliminating the need to get a separate 2D mammogram.

Cost of a 3D Mammogram

Routine breast cancer screening is recommended for women at average risk and those at high risk of breast cancer starting at age 40 and age 30, respectively.

Under the federal regulations for such mammogram screenings, all non-grandfathered Affordable Care Act–compliant major medical health plans (health insurance plans that were already in effect as of March 23, 2010)

are required to pay for mammograms, says Louise Norris , a health policy analyst at Healthinsuran ce.org . While this coverage typically applies to 2D mammograms, some health plans also cover the cost of screenings using 3D mammograms. Some state-regulated health plans may also cover the full cost of 3D screening mammograms, especially in cases where a person is considered to be at high risk for breast cancer.

On average, the out-of-pocket cost for mammograms is about $150.

Cotes says that it can still go higher or lower than this range, depending on your healthcare provider and insurance coverage.

The Takeaway

More than half of mammograms performed in the United States are now 3D mammograms. Either form of mammography is considered an adequate screening method, but research suggests that 3D mammography is more accurate than 2D mammography. Speak with your doctor about the best breast cancer screening test for you, depending on your age and risk factors.

Resources We Trust

• Mayo Clinic: Dense Breast Tissue: What It Means to Have Dense Breasts
• Yale Medicine: Digital Breast Tomosynthesis (3D Mammography)
• American Cancer Society: Getting Called Back After a Mammogram
• Northwestern Medicine: Why Choose 3D Mammography
• University of California in San Francisco: 3D Mammography Technique Benefits Some Women, Not All

Editorial Sources and Fact-Checking

Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy . We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.

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