How is ultrasound used to detect breast cancer?

Some studies have shown that ultrasound can enhance cancer detection rates when used in addition to mammography. Ultrasound uses sound waves to create an image of the breast tissue. If an abnormality (such as an area of increased density) appears on a mammogram, ultrasound may be warranted for further evaluation. If a woman has a palpable mass but nothing is detected by mammography, particularly in women with dense breast tissue, ultrasound should be performed.