Breast ultrasound is a noninvasive diagnostic exam that produces images, which are used to assess breast tissue. Ultrasound may also be used to assess blood flow to areas inside the breasts. The examination is often used along with mammography.

A breast ultrasound procedure is commonly performed to determine if an abnormality detected by mammography or a palpable lump is a fluid-filled cyst or a solid tumor (benign or malignant). Breast ultrasound may also be used to identify masses in women whose breast tissue is too dense to be measured accurately by mammography. Breast ultrasound is generally not used as a screening tool for breast cancer detection because it does not always detect some early signs of cancer such as microcalcifications, which are tiny calcium deposits.