Sonography of the breast.

Quality mammography remains the primary modality used to image the breast. Sonography currently is the most useful adjunctive technique to mammography, having roles in differentiating cystic from solid masses and in guiding interventional procedures. This article reviews these and other indications for breast ultrasound studies, including evaluation of palpable masses not visible in radiographically dense breasts, masses not completely evaluable with mammography, young patients especially susceptible to radiation damage, and abscesses. Ultrasound interpretation of cysts and solid masses are discussed, as are the relative disadvantages of ultrasound as a breast cancer screening tool.