Mammography

What is a mammogram?

A mammogram is an x-ray examination of the breast. It is used to detect and diagnose breast disease in women who either have breast problems such as a lump, pain, or nipple discharge, as well as for women who have no breast complaints.

Mammography cannot prove that an abnormal area is cancer, but if it raises a significant suspicion of cancer, tissue will be removed for a biopsy. Tissue may be removed by needle or open surgical biopsy and examined under a microscope to determine if it is cancer.

Mammography has been used for about 40 years, and in the past 15 years technical advancements have greatly improved both the technique and results. Today, dedicated equipment, used only for breast x-rays, produces studies that are high in quality but low in radiation dose. Radiation risks are considered to be negligible.

What are the different types of mammograms?

According to the National Cancer Institute:

  • screening mammogram
    A screening mammogram is an x-ray of the breast used to detect breast changes in women who have no signs of breast cancer. It usually involves two x-rays of each breast. Using a mammogram, it is possible to detect a tumor that cannot be felt.
  • diagnostic mammogram
    A diagnostic mammogram is an x-ray of the breast used to diagnose unusual breast changes, such as: a lump, pain, nipple thickening or discharge, or a change in breast size or shape. More pictures are taken than during a screening mammogram.

    A diagnostic mammogram is also used to evaluate abnormalities detected on a screening mammogram. It is a basic medical tool and is appropriate in the workup of breast changes, regardless of a woman's age.

The recent development of digital mammography technology shows promise for improved breast imaging. Digital mammography provides electronic images of the breasts that can be enhanced by computer technology, stored on computers, and even transmitted electronically in situations where remote access to the mammogram is required.

How is mammography performed?

X-rays of the breast are different than those used than for other parts of the body. The breast x-ray does not penetrate tissue as easily as the x-ray used for routine x-rays of other parts of the body. The breast is compressed by the mammogram equipment to spread the tissue apart. This allows for a lower dose of radiation. Compression of the breast may cause temporary discomfort, but is necessary to produce a good mammogram. The compression only lasts for a few seconds for each image of the breast.

A breast health nurse or x-ray technologist usually takes the x-rays, but the resulting films are read and interpreted by a radiologist, who reports the results to your physician.

What conditions does a mammogram show?

Picture of mammogram of the breast indicating a cancerous lump
  • Calcifications, tiny mineral deposits within the breast tissue. There are two categories of calcifications:
    • macrocalcifications - coarse calcium deposits that usually indicate degenerative changes in the breasts, such as:
      • aging of the breast arteries
      • old injuries
      • inflammations
    • microcalcifications - tiny (less than 1/50 of an inch) specks of calcium. When many microcalcifications are seen in one area, they are referred to as a cluster.
  • Masses, which may occur with or without associated calcifications, and may be due to different causes, including:
    • cyst - a non-cancerous collection of fluid in the breast. It cannot be diagnosed by physical exam alone or by mammography alone. Either breast ultrasound or aspiration with a needle is required. If a mass is not a cyst, then further imaging may be obtained.
    • benign breast conditions - masses can be monitored with periodic mammography, but others may require immediate or delayed biopsy.
    • Breast cancer

Who should get a screening mammogram?

The American Cancer Society recommends the following screening guidelines for early detection of cancer in women who have no symptoms:

  • Annual mammograms starting at age 40. The age which screening should be stopped is considered on an individual basis according to potential risks and benefits of screening based on a woman's individual overall health status.
  • A clinical breast exam should be part of a regularly scheduled health examination about every three years in a woman's twenties and thirties and every year for a woman in her forties and older.
  • Women should know how their breasts normally feel and look and report any breast change right away to their health care provider. Breast self-exam is an option for women beginning in their twenties.
  • Women who are at an increased risk (family history, genetic tendency, past breast cancer) should talk with their physicians about the benefits and limitations of starting mammography screening earlier, having additional tests breast ultrasound, MRI), or having more frequent exams.

National Cancer Institute Guideline for Screening Mammography

American Cancer Society Guideline for Screening Mammography

Women age 40 and older should have a screening mammogram on a regular basis, every one to two years.

Women 40 years of age and older should have a screening mammogram every year.

Consult your physician regarding the screening guidelines that are appropriate for you.

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