MAMMOGRAPHY


Introduction

Mammography refers to x-ray examination of the breast. Mammography is used to detect and diagnose breast disease both in women who have breast symptoms (problems such as a lump, pain or nipple discharge) and women who are asymptomatic (no breast complaints).

Although breast x-rays have been performed for more than 70 years, modern mammography has only existed since 1969, the year the first x-ray units dedicated to breast imaging were available. Since that time there has been tremendous technical advancement, so that today's examination differs markedly even from those of the mid-1980s. Modern film screen technique uses dedicated equipment (that is, a machine used only for breast x-rays) to produce studies that are high in quality but low in radiation dose, usually about 0.1 to 0.2 rad dose per picture. In the past there were concerns about radiation risks; today if there is a risk, it is negligible. In order to x-ray the breast, a different type of x-ray must be used than for other parts of the body. This x-ray does not penetrate tissue as easily as the x-ray used for routine chest films or x-rays of the limbs (arms, legs). To put dose into perspective, a woman who receives radiation as a treatment for breast cancer will receive several thousands rads. If a woman had yearly mammograms beginning at age 40 years and continuing until 90, she will have received 10 rads.

The breast is compressed to spread the tissue apart and to allow a lower dose of x-ray. Although this may be temporarily uncomfortable, it is necessary in order to produce a good mammogram. The compression is only in place a few seconds of the examination and the entire procedure for screening mammography takes about 20 minutes.

 

The x-ray machine for mammography

This procedure produces a black and white image of the breast tissue on a large sheet of film, which is "read" or interpreted by a radiologist. Radiologists are physicians who specialize in diagnosing diseases by examining images of the inside of the body produced using x-rays, sound waves, magnetic fields and other methods. In addition, other physicians involved in treating breast diseases may also review the mammogram. Reading mammograms is difficult because of the wide range of what is considered normal. A mammogram is like a fingerprint; the appearance of the breast on a mammogram varies tremendously from woman to woman. And, some breast cancers may produce changes in the mammogram that are subtle and difficult to recognize. It is extremely helpful for the radiologist to have films from previous examinations available (not just the report) for comparison purposes. This will help the doctor to recognize small changes and detect a cancer as early as possible.

Calcifications are tiny mineral deposits within the breast tissue, which appears as small white spots on the films. Calcifications are divided into two categories, macrocalcifications and microcalcifications. Macrocalcifications are coarse (larger) calcium deposits that most likely represent degenerative changes in the breasts, such as aging of the breast arteries, old injuries, or inflammations. These deposits are associated with benign (noncancerous) conditions and do not require a biopsy. Macrocalcifications are found in about 50 % of women over the age of 50, and in about 10 % of women under the age of 50.

Microcalcifications are tiny (less than 1/50 of an inch) specks of calcium in the breast. An area of microcalcification that is seen on a mammogram does not always mean that cancer is present. They may appear singly or in clusters. The shape and arrangement of microcalcifications help the radiologist judge the likelihood of cancer being present. In some cases, the microcalcifications do not even indicate a need for a biopsy. Instead, a doctor may advise a follow-up mammogram within 3 to 6 months. In other cases, the microcalcifications are more suspicious and a biopsy is recommended.

Another important change seen on mammograms is the presence of a mass, which may occur with or without associated calcifications. Masses can be due to many things, including cysts. A cyst, which is a benign collection of fluid in the breast, cannot be diagnosed by physical exam alone nor can it be diagnosed by mammography alone. To confirm that a mass is a cyst, either breastultrasound or aspiration with a needle is required. If a mass is not a cyst, then further imaging may be obtained. As with calcifications, a mass can be caused by benign breast conditions or by breast cancer. Some masses can be monitored with periodic mammography while others may require immediate or delayed biopsy. The size, shape, and margins (edges) of the mass help the radiologist in evaluating the likelihood of cancer. Breast ultrasound is often helpful. Prior mammograms may help show that a mass is unchanged for many years, indicating a benign condition and helping to avoid unnecessary biopsy. Having prior mammograms available to the radiologist, as discussed above, is very important.

Mammography cannot prove that an abnormal area is cancer. If mammography raises a significant suspicion of cancer, tissue must be removed for examination under the microscope to tell if it is cancer. This can be done with needle biopsy or open surgical biopsy.

Tips for Mammograms

The following are useful suggestions for assuring that you will receive a quality mammogram:

  1. Ask to see the FDA certificate that is issued to all facilities that meet high professional standards of safety and quality.

     

  2. Use a facility that either specializes in mammography or performs many mammograms a day.

     

  3. If you are satisfied that the facility is of high quality, continue to go there on a regular basis so that your mammograms can be compared from year to year.

     

  4. If you change facilities, ask for your old mammograms to bring with you to the new facility so that they can be compared to the new ones.

     

  5. Don't wear deodorant, powder or cream, under your arms - it may interfere with the quality of the mammogram. If there is breast tenderness, schedule mammogram 10 days after onset of menstrual cycle.

     

  6. Bring a list of the places, dates of mammograms, biopsies, or other breast treatments you have had before.

     

  7. If you do not hear from your physician within 10 days, do not assume that your mammogram was normal - confirm this by calling your physician or the facility.

     

8 Things to Expect When You Get A Mammogram

  1. Mammogram costs, or a percentage of them, are covered by Medicare, Medicaid, and most private health plans. Low cost mammograms are available in most communities. Call the American Cancer Society at 1-800-ACS-2345 for information about facilities in your area.

  2. The procedure requires that you undress above the waist. A wrap will be provided by the facility for you to wear.

  3. A technologist will be present to position your breasts for the mammogram. Most technologists are women. You and the technologist are the only ones present during the mammogram.

  4. The procedure takes about 20 minutes. The actual breast compression only lasts a few seconds.

  5. You may feel some discomfort when your breasts are compressed, but you should not feel pain. To help lessen discomfort, don't have a mammogram just before or during your menstrual period. If you experience pain during the mammogram, tell the technologist.

  6. All mammography facilities are now required to send your results to you within 30 days. You will be usually be contacted within 5 working days if there is a problem with the mammogram.

  7. Only 1 or 2 mammograms out of every 1,000 lead to a diagnosis of cancer. Approximately 10% of women will require additional mammography. Don't be alarmed if this happens to you. Only 8%-10% of those women will need a biopsy, and 80% of those biopsies will not be cancer.

  8. If you are a woman and age 40 or over, you should get a mammogram every year. You can schedule the next one while you're there at the facility and/or request a reminder.

Diagnostic Mammography

Diagnostic mammography is an x-ray examination of the breast in a woman who either has a breast complaint (for example, a breast mass, nipple discharge, etc.) or has had an abnormality found during screening mammography. During diagnostic mammography, additional pictures will be taken to carefully evaluate the breast abnormality. In some cases, special images known as cone views with magnification are used to make a small area of altered breast tissue easier to evaluate. Many other types of x-ray pictures can be obtained, depending on the type of abnormality and its location in the breast. These x-rays are tailored to the patient's needs. A diagnostic mammography work-up may show that a lesion (area of abnormal tissue) has a high likelihood of being benign (not cancer). For these, it is common to ask the woman to return earlier than usual for a recheck, usually in 6 months. On the other hand, a diagnostic mammogram may show that the abnormality is not worrisome at all and the woman can then return to routine yearly screening. Finally, the diagnostic work-up may suggest that a biopsy is needed to tell whether or not the lesion is cancer. A recommendation for biopsy does not necessarily mean that the abnormality is cancer. About 70% of all breast lesions that are evaluated with biopsy are found to be benign when evaluated under the microscope. If a biopsy is recommended, the woman should discuss the different types of biopsy with her physician to determine which method of biopsy is best for her.

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