Women who have been diagnosed previously with cancer in one breast are about five times more likely to develop a tumor in the other breast. Therefore, screening is especially important for those at such high risk. Current screening mainly includes conventional mammography, ultrasonography and physical examination. However, these techniques are not very sensitive in detecting the types of lesions present, particularly in dense breasts.Contrast material-enhanced MR mammography has been shown to have increased sensitivity compared with traditional methods, but its use with contralateral breasts is not well-known. Dr. Federica Pediconi from the University of Rome and her colleagues evaluated the accuracy of using MR mammography with the contrast agent gadobenate dimeglumine for detecting contralateral breast cancer. The scientists chose gadobenate dimeglumine because recent research has shown that, compared with the standard, but similar, agent, gadopentetate dimeglumine, gadobenate dimeglumine provides better images of the malignancies with MR mammography. As reported in the June issue of Radiology, they tested 118 women who had been diagnosed with breast cancer or who had high-risk lesions in one breast. MR mammographic examinations were performed with a 1.5-T magnet from Siemens AG of Erlangen, Germany, both before injection of the contrast agent and at 0, 2, 4, 6 and 8 min afterward.The technique revealed contralateral lesions in 28 of the patients, and 24 of these were detected in patients with dense breasts. Histology confirmed that 22 of the lesions were malignant and six benign. Follow-up examinations at 12 to 24 months confirmed the absence of lesions in the other 90 patients, proving that the technique also did not miss any lesions.The researchers believe that the results indicate that contrast-enhanced MR mammography is a more effective and accurate tool for detecting contralateral breast cancer or high-risk lesions than the more conventional techniques.