Breast disease: the radiologist's expanding role.

The role of the diagnostic radiologist in breast cancer has expanded during the eight-decade history of breast imaging. The radiologist's role now encompasses both breast cancer diagnosis and treatment. This article traces the expansion of the radiologist's role through the history of mammography. The current roles of the radiologist in breast cancer diagnosis are discussed, including screening mammography in the asymptomatic patient, problem-solving breast imaging, breast ultrasound, and galactography. The radiologist's roles in breast cancer treatment that are discussed include preoperative needle localization, percutaneous breast biopsy, and evaluation of the postoperative breast.