Breast cancer

Mammography

Normal breast tissue as it appears on a mammogram

Malignant calcifications as they appear on mammogram

Mammography is a screening tool that searches for cancer when symptoms may not be apparent. A mammogram detects lumps, changes in breast tissue or calcifications too small to be found in a physical exam.

A woman at high risk of breast cancer because her mother or sister was diagnosed with the disease should have her first mammogram at age 40 or 10 years before the age at which the relative was diagnosed, whichever comes first.

The three Mayo Clinic sites combined perform more than 65,000 mammograms each year.

Mammograms

A mammogram is an X-ray that finds abnormalities within the breast tissue. Mammograms use the lowest dose of radiation possible.

A woman's first mammogram is called a baseline mammogram. All future mammograms are compared to the first. A physician may determine if there have been changes in the breast tissue.

At Mayo Clinic, a specially trained radiology technologist performs mammograms. During a mammogram, the breast is positioned in the screening equipment and compressed or flattened to provide a clear picture of the tissue. Usually two images are taken of each breast, from different angles. Compression may be uncomfortable for the few seconds while the X-ray is taken. Some women may feel sore after a mammogram.

Many patients have dense normal breast tissue, which appears white on mammogram images. Abnormal tissue also appears white on mammography. Because it may be difficult to distinguish dense normal tissue from abnormal tissue, the radiologist who interprets the mammogram may also order an ultrasound scan or, in special situations, a magnetic resonance (MR) scan of the patient's breast. Additional images of the breast tissue are often required to interpret results accurately. Although unsettling, this request is not unusual. It simply provides the images needed for accurate results.