Comparative Performance of Molecular Breast Imaging (MBI) to Magnetic Resonance Imaging (MRI) of the Breast in Identifying and Excluding Breast Carcinoma in Women at High Risk for Breast Cancer

Inclusion Criteria: * The subjects to be studied will include female patients ages 18 and older of any race, identified as carrying an elevated risk for breast cancer referred to MDACC. * High risk may be defined as having a calculated lifetime risk \>20%, histopathology of lobular neoplasia or atypical ductal hyperplasia, atypia NOS or a genetic mutation known to predispose the patient to breast cancer. * Subject who are scheduled for a Breast MRI who are willing to participate fully in all aspects of the study including completing both a Breast MRI \& MBI screening exam within a two-week time window, a biopsy of any positive findings and complete a post examination survey. Consent for the enrollment may be obtained upon scheduling the MRI examination. For non-English speakers, a language interpreter will assist in translation. * Written consent will be obtained from all participants to obtain MBI of the breasts and biopsy as indicated, based on findings. All participants will be asked to provide a post examination survey of their experience with both tests. Exclusion Criteria: * Subjects who are pregnant will be excluded as MBI exam involves injection of radioactive tracer * contrast enhanced MRI involves gadolinium injection, both of which are contraindicated during pregnancy.