MR imaging of the breast

The current strategy for breast cancer treatment involves early detection of the neoplasm before it has metastasized outside the breast, and surgical treatment of the lesion that minimizes deformity. Conventional methods of diagnostic imaging of the breast, including mammography, sonography, and galactography, do not adequately address clinical needs with regard to lesion characterization and staging. Magnetic resonance (MR) imaging has been proposed as a modality that may address these needs. The potential clinical uses of MR imaging are defined in terms of clinical needs and technologic requirements. Applications of MR imaging in detection of breast lesions can be divided into two major approaches based on the clinical questions to be answered: (a) improved specificity and (b) improved sensitivity. These approaches are defined by specific sets of clinical needs and have substantially different technologic requirements. The specificity approach is used to reduce the number of biopsies performed to confirm false-positive mammographic findings. The MR imaging device that is used to improve specificity must visualize only the lesions that are seen mammographically. The sensitivity approach requires the visualization of lesions not identified at mammography, so that breast disease can be more effectively staged for treatment. The technologic requirements for the sensitivity approach are considerably more rigorous because all lesions must be identified. The advantages and disadvantages of each of these approaches and the potential clinical ramifications are described.