Clinical utility of breast magnetic resonance imaging in patients presenting with primary breast cancer.

Since magnetic resonance imaging (MRI) of the breast has been shown to be sensitive in identifying the extent of the primary tumor and other foci of cancer, we examined its clinical utility in the surgical management of breast cancer patients. From January 2004 to April 2007, 117 patients with newly diagnosed breast cancer underwent bilateral MRI prior to definitive surgical management. Additional lesions were found in 27 patients (23.1%) in the ipsilateral breast and 19 patients (16.2%) in the contralateral breast. Twelve patients (10.3%) had more than one new lesion identified. Six patients (5.1%) had a larger area of tumor than detected by mammography or ultrasound. Additional biopsies were performed in 27 patients (23.1%). Additional foci of cancer were identified in 17 patients (14.5%): 12 (10.2%) in the ipsilateral breast and 5 (4.3%) in the contralateral breast. This information changed the clinical management in 23 cases (19.7%). Further studies are needed to confirm the benefits of MRI relative to its costs and to further identify the appropriate patients to undergo this imaging procedure.