Ultrasound of the breast helps to distinguish fluid filled lumps in the breast (cysts), from solid lumps which may be cancerous or benign (non-cancerous). It is often useful to examine the breasts of younger women because the breast tissue is much denser than it is in older women, and this density can make it harder to detect an abnormality if a mammogram is performed.
Ultrasound is also used to diagnose problems such as complications from mastitis (an infection that occurs most often during breastfeeding), to assess abnormal nipple discharge, problems with breast implants, and to guide the placement of a needle during biopsies.