Risks
Risks and limitations of mammograms include:
Mammograms use a small amount of radiation
A mammogram exposes you to a very low dose of radiation. For most people, the benefits of regular mammograms are greater than the risks of exposure to this low dose of radiation.
Having a mammogram may lead to more testing
If your healthcare professional finds something that's not expected on your mammogram, you may need other tests. These tests might include extra imaging tests, such as an ultrasound, or a procedure called a biopsy to take a sample of breast tissue for lab testing. However, most findings from mammograms aren't cancer.
If your mammogram shows something concerning, the doctor who examines the images, called a radiologist, may want to compare them with previous mammograms. If you have had mammograms at other facilities, your radiologist may ask for your permission to get those images.
Screening mammography can't detect all cancers
Some cancers found during a physical exam may not be seen on a mammogram. A cancer may be missed if it is too small or if it is in an area that is hard to see with mammography, such as the armpit.
Not all cancers found on mammograms can be cured
Some breast cancers are aggressive, grow rapidly and quickly spread to other parts of the body. Finding breast cancer on a mammogram doesn't always lead to a cure.
How you prepare
To prepare for a mammogram:
- Schedule the test for a time when your breasts are least tender. If you menstruate, that's usually during the week after your menstrual period.
- Bring your prior mammogram images. If you're going to a new facility for your mammogram, ask to have any prior mammograms placed on a CD. Bring the CD with you to your appointment so that the radiologist can compare past mammograms with your new images.
- Do not use deodorant before your mammogram. Avoid using deodorants, antiperspirants, talcum powders or lotions under your arms or on your breasts. Sometimes these products can show up on a mammogram and cause confusion.
What you can expect
Video: Mammogram for breast cancer — What to expect
A mammogram is a picture of your breast taken with a safe, low-dose X-ray machine.
Your technologist will ask you to stand facing the mammography machine, and then place one breast at a time on a flat surface. Another flat surface — called a compression paddle — will gently be lowered into place to compress your breast.
Compression is necessary to spread out the breast tissue and to eliminate motion, which may blur the image. The compression may be uncomfortable, but shouldn't hurt. Compression usually lasts no more than a few seconds.
During this time, an X-ray beam comes from above and penetrates your breast tissue. The X-ray image is either created on a film cassette, located below your breast, or recorded digitally and stored in a computer.
Denser breast tissue, such as cancer or calcifications, appears bright and white, whereas less dense tissue, such as fat, appears dark or gray.
After the X-ray is complete, the compression will release and the technologist will change the angle of the machine. Again, the technologist will position your breast on the flat surface, gently lower the compression paddle and take one more X-ray. This process may be repeated again.
Following the procedure, the images are processed and interpreted by a radiologist. A final report is sent to your doctor.
During the test
At the mammogram facility, you are given a gown and asked to remove neck jewelry and clothing from the waist up.
During the procedure, you stand in front of an X-ray machine made for mammography. A member of your healthcare team places one of your breasts on a platform and adjusts the platform to your height. Your head, arms and torso are positioned to ensure a clear view of your breast.
A clear plastic plate gradually presses your breast against the platform. This pressure lasts for a few seconds to spread out the breast tissue. The pressure isn't harmful, but it can cause some discomfort. Tell your care team if the discomfort becomes too much.
Your breast must be compressed to even out its thickness and allow the X-rays to pass through the breast tissue. The pressure also keeps your breast still, which reduces blurring from movement and lowers the dose of radiation needed. During the brief X-ray exposure, you stay still and hold your breath.
After the test
After your mammogram, you may wait while your care team checks the quality of the images. If the images are not clear, you may have to repeat part of the test. The entire procedure usually takes less than 30 minutes. Afterward, you may dress and resume your usual activities.
Results
Mammography produces mammograms, which are black-and-white images of your breast tissue. Mammograms are digital images that appear on a computer screen. A doctor trained to read imaging tests, called a radiologist, reviews the images.
The radiologist looks for signs of cancer and other conditions that may need further testing, follow-up or treatment. The results are put into a report and shared with your care team. Ask your healthcare professional when and how you will receive the results.
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