Mammography is noninvasive imaging that uses a low-dose X-ray to photograph breast tissue. The result of mammography is a mammogram, which radiologists examine for detecting and diagnosing breast diseases, including:
- Abnormal tissue growth
- Benign tumors
- Cancerous tumors
Screening with a mammogram is important for women who have no symptoms as well as those who are experiencing symptoms, including lumps, pain, or nipple discharge. Mammography is the only proven method for reliably detecting abnormal tissue of the breast. Research shows that annual mammograms can help detect breast cancers early, when they are most curable and it is possible to used breast-conserving therapies.
- Screening Mammography
Screening mammography can show changes in the breast up to 2 years before a patient or physician can feel them. For this reason, it is an excellent way for women to stay on top of their breast health
Current guidelines from the US Department of Health and Human Services (HHS), American Cancer Society (ACS), American Medical Association (AMA), and American College of Radiology (ACR) recommend screening mammography every year for women aged 40 years or more. For women who have had or are at increased risk of breast cancer, the National Cancer Institute recommends seeking expert advice about when to begin and how often to have screening mammography.
- Diagnostic Mammography
Diagnostic mammography is used to evaluate a patient with abnormal clinical findings such as a lump or lumps. Diagnostic mammography often is used to follow up on an abnormal screening mammography
Types of Mammograms
Two recent advances in mammography include digital mammography and computer-aided detection.
- Digital (or full-field digital) mammography converts X-rays into electrical signals. The electrical signals are then used to produce breast images that can be seen on a computer screen or printed on special film
- Computer-aided detection (CAD) uses digitized mammography image from a conventional or digital mammogram. The computer then searches for and highlights abnormalities, including dense or calcified tissue that might indicate cancer
Preparing for Your Mammogram
Before you have a mammogram, be sure to discuss any problems or concerns about your breast health with your doctor.
If you are scheduled to have a mammogram, you should:
- Discuss any symptoms with the X-ray technician
- Tell your doctor and X-ray technician about all surgeries you have had, including breast implants
- Tell you doctor if you have had hormone therapy
- Discuss your family or personal history of breast abnormalities, especially cancers
- Schedule your mammogram the week after your period
- Not wear deodorant, powder, or lotion on your breasts, chest, arms, or underarms as the substances can appear as calcium spots on the mammogram
- Provide your radiologist with all previous mammograms so they can be compared with your newest films
- Ask when you can expect results
- Tell your physician and X-ray technologist if you think you might be or are pregnant.
During mammography, a specially qualified radiologic technologist will position your breast on a special platform. Your breast will then be compressed with a clear plastic paddle to:
- Even the thickness of the tissue
- Spread the tissue as thinly as possible to reveal even the smallest abnormalities
- Hold the breast tissue still for a clear image
- Allow for a lower-dose X-ray
- Reduce X-ray scatter to sharpen the image
You will feel pressure on your breast as the paddle compresses the tissue. Although some patients experience discomfort during a mammogram, the discomfort lasts only seconds.
The technologist will stand behind a glass shield during each X-ray exposure. She will position you between images. You will be asked to hold your breath for a few seconds and be very still to ensure that the images are clear.
When the examination is complete, you will be asked to wait until the technologist is certain he or she has all the images needed for a thorough screening.
Digital mammograms typically take only minutes to complete. They are an outpatient procedure and require no recovery or down time.
Getting Your Results
A radiologist with expertise in mammography will examine your mammograms. He or she will send a report to your primary care or referring physician who will discuss the results with you. You also will receive a letter in the mail with your results.
Benefits and Risks
X-rays are the oldest and most common form of medical imaging. No radiation is left in the patient’s body after an X-ray examination, and X-rays have no side effects.
- Detecting tumors when they are small and easily treatable or cured
- Detecting abnormal tissue growths before they spread to surrounding tissue
- False positive results that require additional mammography or diagnostics such as ultrasound or biopsy to confirm the diagnosis
- False negative results; not all cancers are detected in mammography, and there can be a 5% to 15% rate of false negatives
Limitations of Mammography
Although mammography is the best tool for detecting breast abnormalities, it is not a definitive way of detecting all breast problems, including cancer. If your radiologist discovers a spot that appears abnormal, he or she is likely to recommend additional diagnostic studies. In addition, a breast examination is necessary to identify a palpable mass even with a negative mammogram.
Interpreting mammograms is difficult because breast tissue is different in each individual, images can sometimes be flawed, and not all breast abnormalities appear on mammograms. Because some breast abnormalities are difficult to detect, radiologists often compare current with previous images to identify changes in the tissue.
Both silicone and saline breast implants can make it difficult to read a mammogram. This is especially true if the implant is placed in front of the chest muscle. Technologists have expertise, however, in positioning breasts with implants so that they can obtain the best image possible. Be sure to tell your physician and mammogram technician if you have breast implants.