Ultrasound, also called sonography, is an imaging technique in which high-frequency sound waves are bounced off tissues and internal organs. Their echoes produce a picture called a sonogram. Ultrasound imaging of the breast is sometimes used in conjunction with mammography to evaluate areas of concern. Ultrasound is used to distinguish between solid tumors and fluid-filled cysts.
During an ultrasound examination, the clinician spreads a thin coat of lubricating jelly is spread over the area of the breast to be imaged to improve the conduction of the sound waves. A hand-held device called a transducer directs 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, which can provide an image of a mass within the breast.
Ultrasound is not used for routine breast cancer screening because it does not consistently detect certain early signs of cancer such as microcalcifications (tiny deposits of calcium in the breast that cannot be felt but can be seen on a conventional mammogram). A cluster of microcalcifications may indicate that cancer is present.
Suspicious areas seen on ultrasound examinations may need to be biopsied. Ultrasound may be used to guide the radiologist to these suspicious areas. Tissue collected from the biopsy is sent to pathology for evaluation and exam results may take up to 48 hours.