Breast Ultrasound or sonography uses high-frequency sound waves to produce pictures of the breast and does not expose the patient to radiation. Images are captured in real-time, showing movement and blood flow in the vessels. This painless test evaluates blood flow or lack of flow in a breast mass, providing clues as to the cause of the mass. It is very helpful as a supplementary test to help determine the nature of a breast abnormality that was seen on mammography. The procedure can often determine if the suspicious area is solid, which may or may not indicate a cancerous site, or a fluid-filled sac, such as a cyst. The modality may also be helpful for women with dense breasts, have silicon breast implants, are pregnant or have genetic risks for breast cancer.