Just like a three-dimensional photo is more detailed and lifelike than a 2D image, digital breast tomosynthesis (DBT)—or 3D mammography—gives radiologists a clearer view of breast tissue. And that's why this new technology has rapidly become an essential imaging tool that enhances a doctor's ability to detect early breast cancer. With breast cancer, earlier detection leads to earlier treatment, less aggressive treatment options and better outcomes.
Thanks to 3D mammography, radiologists can view breast images in "slices," which essentially allows them to see straight through tissue layers and makes it less likely they’ll miss an early sign of cancer. Unlike with 2D mammograms, the 3D technology also makes it easier for radiologists to detect breast cancer that is masked by overlapping fibroglandular tissue.
At Yale Medicine, we perform 3D and 2D mammography simultaneously for both screening and diagnostic purposes at our seven breast imaging sites located in New Haven and Fairfield Counties.
What are the benefits of 3D mammography?
There are many benefits of 3D mammograms. Here are some specifics you should know about:
- Tomosynthesis or “tomo” (3D mammography) increases cancer detection. However, increased cancer detection with tomosynthesis is limited in women with extremely dense breasts.
- With 3D mammograms, there are fewer recalls for further testing, which means less unnecessary worry.
What is a 3D mammogram like?
The experience of having 3D mammogram feels exactly the same as having a 2D one. You arrive at the breast center and change into a dressing gown. A radiology technician escorts you into a private mammography room with the 3D mammography machine. (It looks the same as a conventional 2D mammography machine.)
The technician helps you know how to position your body. The breast is supported by a tray while a flexible plastic plate is gently lowered down on top of the breast to press against the breast tissues.
A mammography tube then takes a series of low-radiation dose X-ray images at different angles, all within just a few seconds. The process is repeated for the other breast.
The radiologist reads the images and sends a complete report to you and your doctor with the results.
How long does a 3D mammogram take?
The entire exam is quick (about 15 minutes). The good news for patients is it doesn't take any more time to have her mammogram than usual. Each image only takes a few seconds.
When should I have a mammogram?
Talk to your health care provider about when you should begin having screening mammograms.
Average risk women (including women with dense breasts) should consider starting yearly screening mammography beginning at age 40.
What is a 3D screening mammogram?
Screening mammograms are typically performed every year or two in women over the age of 40 with no signs or symptoms. It’s a way to get a look inside the breasts in order to detect small nodules within breast tissues that may not be felt by the patient or a doctor.
Studies have shown that regular screening mammograms can reduce the mortality from breast cancer in women by about 30 percent or more. That’s because breast cancer is a progressive disease, so detecting it early through mammography allows treatment to begin sooner.
What’s more, for women who opt to have a 3D mammogram, there are added benefits: these mammograms are clinically proven to be more accurate and cause fewer false alarms. Studies have shown a significant reduction in the number of women who are recalled to have more testing (between 15 and 43 percent).
For women whose screening mammogram indicates they have dense breasts, they can also choose to schedule an additional screening test called a breast ultrasound or sonogram. Rest assured, dense breasts are perfectly normal (and half of women have them). But dense breast tissue makes it more difficult for radiologists to detect cancer, so an ultrasound gives another way to check for cancerous lesions.
Many women who know they have dense breasts opt to schedule their future mammograms and ultrasounds back-to-back on the same day. Same-day screening results are also available.
What are diagnostic 3D mammograms?
To the patient, a mammogram is a mammogram—whether it’s a screening or diagnostic mammogram, the experience is similar. But even though they feel the same, diagnostic mammograms have a key difference. Diagnostic mammograms, as their name suggests, are performed for the purpose of assessing a breast-related concerns that have been identified. Often additional images tailored to the specific problem are needed to determine if changes a woman (or man) may experience are cancerous or benign (such as non-cancerous cysts or fibroadenomas).
Common breast problems that may prompt a doctor to recommend a diagnostic mammogram can include a palpable lump felt by the patient or physician, discharge from the nipple, focal persistent breast pain or any suspicious finding a radiologist sees on a screening mammogram, including calcifications (calcium deposits). Same-day results are always available to patients, and a radiologist may discuss the results directly with the patient.
What if a radiologist finds something suspicious when I have a screening 3D mammogram?
Following a screening mammogram, if the radiologist identifies an area that needs to be evaluated closer, you may be called back to the breast center to have more testing. So sometimes patients who’ve had a screening mammogram may need to have a diagnostic mammogram (and/or breast ultrasound) to get a better look.
Depending on what the radiologist finds, a breast biopsy may be needed to obtain a tissue sample to be sent to a pathologist for review. These steps are taken to diagnose or rule out breast cancer. The good news is about 60 to 70 percent of the time breast biopsy results are negative, says Dr. Hooley.
Is the technology used for anything else?
Sometimes tomosynthesis or 3D mammography is also used to guide procedures to diagnose breast cancer initially suspected or detected on mammography; these are called tomosynthesis-guided procedures. “Tomo” can be used to perform image-guided breast biopsies, too.