An ultrasound is an imaging test that uses high frequency sound waves to take pictures of areas inside the body.
An ultrasound helps determine whether a breast abnormality is solid or liquid. A cyst is a benign (not cancerous) mass filled with fluid. Fluid-filled cysts will look different on an ultrasound than a solid mass, such as a breast cancer or a benign fibroadenoma, or even other types of cysts that have some soft tissue and may need further study.
If the ultrasound shows a solid mass, you may need a biopsy or other tests because ultrasound can’t always determine whether a solid lump is cancer. Ultrasound also does not see calcifications well. These are better seen by a mammogram.
If you are under age 30 and you have a lump in your breast, your doctor may recommend you have both an ultrasound and a mammogram. Young women often have dense breast tissue that is filled with glands and benign lumps, not cancers. But ultrasounds are very effective at looking at breast lumps that can be felt.
During an ultrasound, a technologist or doctor will place a probe that makes sound waves onto the breast. The sound waves will go through your breast tissue and project onto a screen as an image. The test does not expose you to radiation.