Breast ultrasound (or sonogram), is frequently used to evaluate breast abnormalities that are found with screening or diagnostic mammography or during a physician performed clinical breast exam. Ultrasound is excellent at imaging cysts: round, fluid-filled, pockets inside the breast. Additionally, ultrasound can often quickly determine if a suspicious area is in fact a cyst (always non-cancerous) or an increased density of solid tissue (dense mass) which may require a biopsy to determine if it is malignant.
Ultrasound is also useful in helping physicians guide a biopsy to determine whether a breast abnormality is cancerous. Physicians use ultrasound during core and fine needle aspiration biopsies to determine where to place the needle. Ultrasound may also be used to prove whether a suspicious area is a lymph node. Lymph nodes have fatty centers which are often apparent on ultrasound images.
Ultrasound uses high frequency sound waves and their echoes to scan organ structures in the body, offering safe, painless and quick diagnostic results without radiation. The technique is similar to the echolocation used by bats, whales and dolphins, as well as SONAR used by submarines. The ultrasound machine transmits high-frequency sound waves into the body. Then the machine displays the distances and intensities of the echoes it receives back on the screen, forming an image.
During an ultrasound examination, the clinician spreads a thin coating of lubricating jelly over the area to be imaged to improve conduction of the sound waves. A hand-held device called a transducer directs the sound waves through the skin toward specific tissues. As the sound waves are reflected back from the tissues within the breast, the patterns formed by the waves create a two-dimensional image of the breast on a computer.