A breast ultrasound uses sound waves to make a picture of the tissues inside the breast. A breast ultrasound can show all areas of the breast, including the area closest to the chest wall, which is hard to study with a mammogram. Breast ultrasound does not use X-rays or other potentially harmful types of radiation.
A breast ultrasound is used to see whether a breast lump is filled with fluid (a cyst) or if it is a solid lump. An ultrasound does not replace the need for a mammogram, but it is often used to check abnormal results from a mammogram.
For a breast ultrasound, a small handheld unit called a transducer is gently passed back and forth over the breast. A computer turns the sound waves into a picture on a TV screen. The picture is called a sonogram or ultrasound scan.
Why It Is Done
Breast ultrasound can add important information to the results of other tests, such as a mammogram or magnetic resonance imaging (MRI). It also may provide information that is not found with a mammogram. A breast ultrasound may be done to:
- Find the cause of breast symptoms, such as pain, swelling, and redness.
- Check a breast lump found on breast self-examination or physical examination. It is used to see whether a breast lump is fluid-filled (a cyst) or if it is a solid lump. A lump that has no fluid or that has fluid with floating particles may need more tests.
- Check abnormal results from a mammogram.
- Look at the breasts in younger women because their breast tissue is often more dense, and a mammogram may not show as much detail.
- Guide the placement of a needle or other tube to drain a collection of fluid (cyst) or pus (abscess), take a sample of breast tissue (biopsy), or guide breast surgery.
- Watch for changes in the size of a cyst or a noncancerous lump (fibroadenoma).
- See how far cancer has spread in a breast.
- Check your breasts if you have silicone breast implants or dense breasts. In these situations, a mammogram may not be able to see breast lumps.
How To Prepare
In general, there's nothing you have to do before this test, unless your doctor tells you to. Wear something that makes it easy to undress above the waist.
How It Is Done
You will be asked to undress above the waist. You will be given a gown to drape around your shoulders. Remove all jewelry from around your neck.
Gel will be put on your breast so the transducer can pick up the sound waves as it is moved back and forth over the breast. A picture of the breast tissue can be seen on a TV screen.
How long the test takes
A breast ultrasound test usually takes 15 to 30 minutes. More time may be needed if a breast exam will be done or if a biopsy is also planned. You may be asked to wait until a radiologist has reviewed the pictures. He or she may want to do more ultrasound views of some areas of your breast.
How It Feels
The gel may feel cold when it is put on your breast. You will feel light pressure from the transducer as it passes over your breast, but you should feel no discomfort unless your breast is tender because of fibrocystic breast changes, an abscess, or another infection. You will not hear the sound waves. A special Doppler ultrasound may be used to check the blood flow to the breast; you can hear the sound waves from this type of ultrasound.
The radiologist may discuss the results of the ultrasound with you right after the test. Complete results are usually available to your doctor in 1 to 2 days.