BREAST-TUMORS - COMPARATIVE ACCURACY OF MR-IMAGING RELATIVE TO MAMMOGRAPHY AND US FOR DEMONSTRATING EXTENT

PURPOSE: To evaluate the comparative accuracy of magnetic resonance (M R) imaging relative to mammography and ultrasonography (US) for assess ing the extent of breast tumors. MATERIALS AND METHODS: Histologic res ults and preoperative imaging findings (mammography, US, MR imaging) w ere analyzed regarding tumor size and multifocality of 61 tumors in 60 women undergoing mastectomy for carcinoma. RESULTS: In 10% of cases, the index tumor was not seen at mammography. With US, 15% of the index tumors were not recognized, while MR imaging missed 2% of the index t umors. On mammographic and VS images, tumor size was underestimated si gnificantly (P < .005), by 14% and 18%, respectively, while MR imaging showed no significant difference in size compared with that found in a pathologic evaluation. Mammography showed 31% of the additional inva sive lesions, while US showed 38% and MR imaging showed 100%. CONCLUSI ON: MR imaging was the most accurate of the three preoperative imaging modalities in assessing the size and number of malignant lesions in t he breast.