Objective: To describe possibilities of the differential diagnosis of breast lesions by using magnetic resonance (MR). Patients and Methods: We compared 117 MR breast findings with histology or cytology and determined the sensitivity, specificity, positive and negative predictive values of MR for the diagnosis of malignant lesions. MR examinations were performed on a 0.5 T imager (Gyrex V Dlx, Elscint) using non-enhanced sequences and dynamic 3D gradient-echo sequence during intravenous administration of 20 ml gadolinium-DTPA (Magnevist, Schering). Results: The sensiti- vity, specificity, positive and negative predictive values of MR were 78.9%, 87.3%, 75.0%, and 89.6%. The main causes of false negative findings were lesions with minimal enhancement after gadolinium administration and technical limitations of our imager. False positive findings were found in benign lesions with high enhancement - fibroadenomas, inflammations, fibrocystic disease and adenosis. Conclusions: Mammography and ultrasound are still the basic methods in imaging of breast lesions, MR is so far complementary. Main indications for MR include the identification of multifocal, multicentric and bilateral lesions, the differential diagnosis between benign and malignant lesions, the differentiation between tumor and scarring after biopsy, operation, or prosthesis implantation, and the assessment of breast prostheses.

        Key words: magnetic resonance - MR - imaging methods - breast disease - breast cancer