Imaging the Breasts


A mammogram is an x-ray exam that uses a low dose of radiation to detect changes and abnormalities in the breast that may not be felt by the woman or her physician. Finding breast cancer early can significantly increase a woman’s chances of successful treatment.

Women should have a baseline mammogram at age 35, then have a mammogram every year after the age of 40. Women known to be at risk for breast cancer may have a mammography more frequently and when they are younger. For example, a woman with a family history of breast cancer should have a mammogram 10 years younger than the age when her relative was diagnosed. (Talk to your doctor if you think you may be at increased risk for breast cancer.) Women who have had breast cancer surgery may still need to have yearly mammograms to examine any remaining breast tissue. Those with breast implants should tell their doctor as this requires a more careful procedure.

During a mammogram, a woman is asked to remove her shirt and bra (the technician may provide a wrap), and her breast is pressed between two plastic plates in order to spread out the breast tissue for easier assessment of abnormalities. This may cause momentary discomfort, and it is recommended that a woman schedule her mammogram shortly after her period when the breasts are less tender. Two x-ray images are then taken of each breast. This process should only take 20 minutes.

A radiologist will then read the images and designate a category 0 through 6, with 1 indicating no findings and 6 indicating that a cancer was known to be present before the mammogram (0 indicates that an image was incomplete and an assessment cannot be made). Patients must be notified of the results within 30 days of the mammogram.

Although most mammography findings are benign (non-cancerous), any findings will probably require further testing such as additional mammogram images, MRI, ultrasound, ductogram, biopsy, or needle aspiration to rule out cancer. Further testing is more frequently required for women with large or dense breasts.


Magnetic resonance imaging (MRI) is a non-invasive technique that uses powerful magnets and radio waves instead of X-rays, as mammograms do, to create images of the body. MR imaging is typically used to further evaluate findings on a mammogram. An MRI is particularly helpful in finding breast abnormalities in women with dense breasts, scar tissue, or implants.

MRI is not a safe choice for everyone, however. People with internal defibrillators, cochlear implants, and clips for brain aneurysm should not receive MR imagining. People with medical devices containing metal and women who may be pregnant should talk to their doctors about the safety of receiving an MRI.

For the MRI, you will be asked to wear a hospital gown or clothing that does not contain metal fasteners. You will also be asked to remove any jewelry, pens, eye glasses, or other metal objects that may interfere with the imaging or fly across the room when the MRI machine is activated.

For a breast MRI, you will lie face down with your breasts in cushioned openings in the exam table. You will not feel anything during the MRI, but if you suffer from claustrophobia, you may wish to ask your doctor about being administered a sedative before the MRI begins. Some radiology centers now offer open-sided MRI exams, which are less confining. When the MRI machine is activated, it will emit a loud thumping noise; some facilities may provide earplugs or headphones. The MRI session should only last 30 minutes to an hour.


Ultrasound imaging uses high-frequency sound waves to produce real-time images of the body. Ultrasound imaging is used to determine whether a breast mass is full of fluid or solid tissue. In addition to viewing breast tissue, Doppler ultrasound can be used to study how blood flows through the body, which gives the physician additional information about flow in and out of a suspicious breast mass.

Ultrasound is a painless, non-invasive technique that is safe for everyone, including those who are not recommended to receive mammography due to contraindications of the use of X-rays or MRI.

For the ultrasound you will be asked to lie on your back with your arm above your head, and your physician will apply a gel to the breast to be examined. A transducer, which resembles a microphone, will be pressed against the breast and moved over the area to be studied. The transducer will then relay the echoes of the sound waves it emits to a nearby computer which produces an image of the breast.

The radiologist performing the exam may speak with you about the results immediately following the exam, or he or she may pass that information on to your referring physician for a follow up discussion.

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