A 3D mammogram (breast tomosynthesis) is an imaging test that combines multiple breast X-rays to create a three-dimensional picture of the breast.
A 3D mammogram is used to look for breast cancer in people who have no signs or symptoms. It can also be used to investigate the cause of breast problems, such as a breast mass, pain and nipple discharge.
When used for breast cancer screening, 3D mammogram machines create 3D images and standard 2D mammogram images. Studies show that combining 3D mammograms with standard mammograms reduces the need for additional imaging and slightly increases the number of cancers detected during screening. But more study is needed to understand whether 3D mammograms may reduce the risk of dying of breast cancer more than a standard mammogram alone.
The 3D mammogram is becoming more common, but it isn't available at all medical facilities.
A 3D mammogram is used as a breast cancer screening test to look for breast cancer in people with no signs or symptoms of the disease. It can also be used to investigate breast problems, such as a suspicious lump or thickening.
When used for breast cancer screening, the 3D mammogram machine creates 3D images and standard 2D mammogram images because both types of images have some advantages in seeing certain breast abnormalities.
Combining a 3D mammogram with a standard mammogram can:
Improve breast cancer detection in dense breast tissue. A 3D mammogram offers advantages in detecting breast cancer in people with dense breast tissue because the 3D image allows doctors to see beyond areas of density.
Breast tissue is composed of milk glands, milk ducts and supportive tissue (dense breast tissue) and fatty tissue. Dense breasts have greater amounts of dense breast tissue than fatty tissue. Both dense breast tissue and cancers appear white on a standard mammogram, which may make breast cancer more difficult to detect in dense breasts.
There isn't enough evidence to conclude that 3D mammograms can reduce the risk of dying of breast cancer more than a standard mammogram alone. For this reason, most guidelines for breast cancer screening don't specify that women should choose 3D mammograms over standard mammograms alone.
A 3D mammogram is a safe procedure. As with every test, it carries certain risks and limitations, such as:
To prepare for your 3D mammogram:
At the testing facility, you're given a gown and asked to remove any necklaces and clothing from the waist up. To make this easier, wear a two-piece outfit that day.
For the procedure itself, you stand in front of an X-ray machine equipped to perform 3D mammograms. The technician places one of your breasts on a platform and raises or lowers the platform to match your height. The technician helps you position your head, arms and torso to allow an unobstructed view of your breast.
Your breast is gradually pressed against the platform by a clear plastic plate. Pressure is applied for a few seconds to spread out the breast tissue. The pressure isn't harmful, but you may find it uncomfortable or even painful. If you have too much discomfort, tell the technician.
Next, the 3D mammogram machine will move above you from one side to the other as it collects images. You may be asked to stand still and hold your breath for a few seconds to minimize movement.
The pressure on your breast is released, and the machine is repositioned to take an image of your breast from the side. Your breast is positioned against the platform again, and the clear plastic plate is used to apply pressure. The camera takes images again. The process is then repeated on the other breast.
The images collected during a 3D mammogram are synthesized by a computer to form a 3D picture of your breast. The 3D mammogram images can be analyzed as a whole or examined in small fractions for greater detail. For breast cancer screening purposes, the machine also creates standard 2D mammogram images.
A doctor who specializes in interpreting imaging tests (radiologist) examines the images to look for abnormalities that may be breast cancer. If the radiologist sees anything unusual, he or she will use your standard mammogram and any older mammogram images that are available to determine whether additional testing is needed.
Additional tests for breast cancer may include an ultrasound, an MRI or, sometimes, a biopsy to remove suspicious cells for testing in a lab by doctors who specialize in analyzing body tissue (pathology testing).