A breast ultrasound uses sound waves to make a picture of the tissues inside the breast and can show all areas of the breast, including the area closest to the chest wall, which is difficult to study with a mammogram. Breast ultrasound does not use x-ray or other potentially harmful types of radiation.
The ultrasound is used to see whether a breast lump is filled with fluid (cyst) or if it is a solid lump. Ultrasounds do not replace the need for a mammogram, but the are often used to check abnormal results from a mammogram.
During this procedure, a small, handheld unit called a transducer is gently passed back and forth over the breast. A computer uses the sound waves to create a picture, which is projected on a screen. The picture is called a sonogram or an ultrasound scan.