Imaging techniques in breast cancer.

In the diagnosis of clinically inapparent breast cancer, mammography remains the most effective imaging modality, which is due in large part to its ability to detect microcalcifications. Of the ancillary modalities, sonography is the most useful because it readily differentiates cysts from other breast lesions. Internal mammary and axillary node imaging have been tried with varying levels of success, but false-positive and false-negative rates remain high with available techniques. Pulmonary metastases are best evaluated by chest X-ray with specificity increased by other imaging techniques. Liver and bone metastases may be screened for with isotope scans with computerized tomography, sonography, and magnetic resonance imaging, increasing the specificity of abnormal scans. CT and MRI are the most effective tools for evaluating CNS disease.