An investigative study was undertaken to determine the potential for a new magnetic resonance (MR) imaging technique, RODEO (rotating delivery of excitation off resonance), for use as a diagnostic imaging tool for the breast. The RODEO technique provides fat suppression with T1 weighting and is ideal for gadolinium-enhanced breast imaging. It is a short repetition time, steady-state sequence for high-resolution three-dimensional acquisitions and provides a clinically efficient imaging time of approximately 5 minutes for 128 sections. Imaging findings were correlated with serially sectioned pathologic specimens in 30 breasts with 47 malignant and 27 benign lesions. MR imaging had a sensitivity of 94% and a specificity of 37%. MR imaging depicted additional cancers not seen at mammography in 11 of the 30 patients (37%). The lesions not seen at mammography varied in size from 3 mm to 12 cm. RODEO MR imaging may be used to improve diagnosis of breast cancer in patients with mammographically dense breasts or silicone implants/injections and to stage disease in patients who are candidates for lumpectomy.