MRI is a sophisticated technology that uses a powerful magnet and radio waves to image tissue. As with ultrasound, there is no radiation exposure. MRI maybe twice as sensitive as mammography in detecting some subtle breast cancers. However, not all cancers that are shown by mammography are demonstrated on MRI. Studies have shown that MRI is helpful in the setting of a newly diagnosed breast cancer, since it can help guide pre-operative planning. MRI is also the optimal method for evaluating breast implant integrity. We also use breast MRI to screen women at high risk for developing breast cancer. The American Cancer Society recommends annual breast MRI screening in conjunction with mammography for women with a 20% or greater lifetime risk of breast cancer. This include some women with a personal or family history of breast or ovarian cancer, women who have had radiation treatment to the chest and women with BRCA1 or BRCA2 genes.