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Breast Ultrasound

Medically reviewed by Last updated on Nov 27, 2023.

What is the test?

Harvard Health Publishing

Ultrasound uses sound waves instead of radiation to generate snapshots or moving pictures of structures inside the body. This imaging technique works in a manner similar to radar and sonar. Ultrasound was developed in World War II to detect airplanes, missiles, and submarines that were otherwise invisible.

The doctor or ultrasound technician first coats a small area of your skin with a lubricant to reduce friction. He or she then places an ultrasound transducer, which looks like a microphone, on your skin and may rub it back and forth to get the right view. The transducer sends sound waves into your body and picks up the echoes of the sound waves as they bounce off internal organs and tissue. A computer transforms these echoes into an image that is displayed on a monitor.

A breast ultrasound can indicate whether a breast lump is caused by a fluid-filled cyst or a solid mass, such as cancer.

How do I prepare for the test?

No preparation is necessary.

What happens when the test is performed?

As you lie on your back on a table, a technician or doctor squirts some clear jelly onto your skin to help the ultrasound sensor slide around easily. He or she then places the sensor against your skin. An image of your breast appears on a video screen. The technician or doctor moves the sensor back and forth over the area of the breast needing examination. This allows the doctor to see the tissue inside from different views.

Sometimes the findings on an ultrasound make drainage of a cyst or a biopsy of a breast lump a prudent idea. In this event, if your doctor requested a biopsy during the ultrasound, your skin will be cleaned with alcohol or another disinfectant. The doctor doing the procedure may inject a local anesthetic. But even without this numbing medicine, you should feel little pain.

Next, the doctor gently pinches your breast to hold the lump steady. He or she inserts a thin needle into the lump. The needle is attached to a syringe, a suction device that "aspirates" or pulls fluid and/or cells through the needle. The sample is sucked back into the syringe. To get a good sample, the doctor may need to move the needle in and out of the lump several times.

What risks are there from the test?

There are no risks from ultrasound. If your ultrasound is followed by a biopsy, you might have a small amount of bruising where the needle was inserted. There may be some soreness afterward.

Must I do anything special after the test is over?


How long before the result of the test is known?

Sometimes the results of a breast ultrasound are reported to you immediately. If a technician performs the test you may not get specific information about the study until a radiologist is able to read the images. If a biopsy has been done, you should have information from the test within a few days. If the cells removed during an aspiration are not cancerous but the lump feels questionable or appears suspicious on your ultrasound, the doctor may recommend further testing with a large core needle biopsy or surgical biopsy.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.