Additional Study Information: This is a study for patients diagnosed with either breast cancer that is HER-2 positive, or breast cancer that is negative for estrogen, progesterone and HER-2 (triple-negative disease), and whose tumor can be removed by breast-conserving surgery. The purpose of this study is to test whether patients undergoing a breast MRI (magnetic resonance imaging) before breast surgery will have better results after the surgery. MRI is a medical imaging method that uses magnets to make images of the body. MRI helps doctors to tell the difference between cancer and normal tissue in the body. MRI uses dyes (contrast agents) that are injected into the veins to help create the images of the body's tissues. Breast tumors are routinely evaluated using mammograms and ultrasound before surgery. This study would like to find out if using MRI in addition to mammography before surgery improves our ability to evaluate tumors and decide what kind of surgery is best for the patient. The goals of this study are: - To see if using MRI improves decision-making when choosing what type of surgery is best for the patient (mastectomy or lumpectomy). - To see if using MRI affects how well patients do after surgery. - To examine the effect of using MRI on patients quality of life. - To examine the effect of MRI on overall medical costs. About 536 people will take part in this study. About 20 subjects will be enrolled at Columbia University Medical Center.