A Part of the University of Maryland Medical Center

Connect with UMGCC
Facebook Twitter YouTube Blog iPhone
Email PageEmail page Print PagePrint page

Breast Evaluation and Treatment

Prevention and Early Detection of Breast Cancer


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 30 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, produce studies that are high in quality but low in radiation dose. Radiation risks are considered to be negligible.

Two kinds of mammograms:

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.

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.

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.

How is mammography performed?
X-rays of the breast are different than those used 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?

Calcifications - tiny mineral deposits within the breast tissue. There are two categories of calcifications:

  • aging of the breast arteries
  • old injuries
  • inflammations

Masses - may occur with or without associated calcifications, and may be due to different causes, including:


Guidelines for Screening Mammography:

National Cancer Institute Guideline - Women in their 40s and older should have a screening mammogram on a regular basis, every 1 to 2 years.

American Cancer Society Guideline - Women 40 years of age and older should have a screening mammogram every year.

This page was last updated on: August 21, 2009.