A breast ultrasound is a test that uses high-frequency sound waves to form images of tissues and other structures inside the breast.
Who is a candidate for the test?
Healthcare professionals may recommend this test so that they can:
An ultrasound may also be used to evaluate a woman who has possible signs of breast cancer. In some cases, this test is used instead of a mammogram. Some examples of when this test might be used include:
a pregnant woman whose unborn child could be harmed by the radiation of a mammogram
a woman who refuses a mammogram due to fear of radiation
a woman whose silicone breast implants may interfere with a mammogram
a woman younger than 25 years, because younger women often have dense breast tissue that is difficult to see clearly on a mammogram
How is the test performed?
The test takes about 15 minutes. A healthcare professional can perform this test in an office, clinic, or hospital. Usually, a woman puts on a hospital gown that opens at the front before the test.
There are two ways to perform the test:
The woman lies on her stomach on a special exam table. Set into part of the table is a tank of heated water. The woman places her breast into the water. The person performing the test places a scanning tool that sends out sound waves at the bottom of the tank.
OR: The woman lies on her back. The healthcare professional puts a small portion of gel on the woman's breast. This gel helps transmit sound waves. Next, the examiner takes a scanning tool that sends out sound waves and moves it around on the breast.
In either method, the sound waves bounce off internal tissues of the breast and then return to the scanning tool.
A computer converts the sound waves into a black-and-white image. The healthcare professional can then read this image of the internal part of the breast. In some cases at the time of the ultrasound, a doctor may insert a needle into the breast to obtain tissue for a breast biopsy or cystic fluid for analysis. The images from the ultrasound help guide the needle into the right area of the breast. When the test is finished, the healthcare professional will dry the breast or wipe the gel off. The woman may then dress and leave.
What is involved in preparation for the test?
On the day of the test, the woman should not put any lotions or powders on her breast. No other preparation is generally required.
What do the test results mean?
Test results are usually sent to the woman's healthcare professional, who then discusses them with her. In some cases, ultrasound will show no problem in the breast. Abnormal findings may include:
a benign cyst, which means the lump or mass is not cancer
an abscess, or pus-filled pocket, in the breast
breast cancer, which can only be diagnosed for certain if a needle was used to sample a piece of the breast tissue
fibrocystic breast disease, which causes benign lumps in the breast
other benign tumors, such as adenomas
American Institute of Ultrasound in Medicine. "Ultrasound-General Information" Last updated 3/23/00.
Anderson KN, Anderson LE, Glanze WD. Mosby's medical, nursing, and allied health dictionary, 5th ed. St. Louis, Missouri: Mosby-Year Book, Inc., 1998.
Miller BF, Keane, CB. Encyclopedia and dictionary of medicine, nursing, and allied health, 4th ed. Philadelphia, Pennsylvania: WB Saunders Company, 1987.
Pagana KD and Pagana T. Mosby's manual of diagnostic and laboratory tests, 4th ed. St. Louis: Mosby, 1998.