A breast ultrasound is an imaging technique used to screen for tumors and other breast abnormalities. The ultrasound uses high-frequency sound waves to produce live images of the inside of your breast. Unlike X-rays and CT scans, ultrasounds use no radiation and are considered safe for pregnant women and nursing mothers.
In addition to determining the nature of a breast abnormality or screening for breast cancer, ultrasounds can also be used to help guide a surgeon while he or she removes a tissue sample from a lump in the breast. This is called an ultrasound-guided core needle biopsy.
A breast ultrasound will be performed if you or your doctor discovers a suspicious mass in your breast. The ultrasound helps determine the location and size of the mass. While a breast lump may be frightening, according to the Mayo Clinic, approximately four out of five breast lumps are benign (non-cancerous) (Mayo Clinic).
Ultrasounds and other imaging techniques cannot determine if the mass in your breast is cancerous. That can only be established if a sample of the mass is removed (usually through a breast biopsy) and tested in a laboratory.
Because this imaging technique uses absolutely no radiation, a breast ultrasound carries no risks. Radiation tests aren’t considered safe for pregnant women, so an ultrasound is the preferred method of breast examination for women who are pregnant. In fact, the test involves the same kind of ultrasound waves used to monitor the development of a fetus.
Preparation for a breast ultrasound is minimal. Because you’ll need to expose your breasts during the test, it’s best to wear a two-piece outfit to your appointment.
Also, don’t apply creams, lotions, or other cosmetics on the skin of your breasts. This can interfere with the test procedure.
Before the ultrasound, your doctor will examine your breast. Then, you’ll be asked to undress from the waist up and lie on your back on an ultrasound table.
Your doctor will apply a clear gel to your breast. This conductive gel helps the sound waves travel through your skin. The doctor will then move a wand-like device called a transducer over your breast.
The transducer sends and receives high-frequency sound waves. As the waves bounce off your breast’s internal structures, the transducer records changes in their pitch and direction, creating a real-time recording of the inside of your breast on a computer monitor.
When the images have been recorded, your doctor will clean the gel off your breast and allow you to get dressed.
The images from a breast ultrasound are in black and white. Cysts, tumors, and growths will appear dark on the scan.
Just because there is a dark spot on your ultrasound, it doesn’t mean that you have breast cancer. The majority of breast lumps are noncancerous, so more testing is needed to determine whether the lump is malignant.
There are several conditions that can cause benign lumps in the breast, including:
- adenofibroma: a benign tumor of the breast tissue
- fibrocystic breast disease: painful, lumpy breasts caused by hormone changes
- intraductal papilloma: small, benign tumors of the milk ducts
- mammary fat necrosis: lumps formed by bruised, dead, or injured fat tissue
While the fuzzy images may be difficult for you to interpret, a trained radiologist will review the results and send them to your doctor.
If your doctor finds a mass that requires further testing, he or she may order a biopsy that may be performed on the same day. During the procedure, your doctor may use an ultrasound to guide the biopsy needle.