The primary hypothesis of this project is that using molecular breast imaging (MBI) in evaluating women with equivocal mammographic or sonographic findings will demonstrate high specificity in distinguishing benign from malignant breast disease and, as a result, decrease the number of biopsies.

Inclusion Criteria:

• 18 years of age or older
• Women who have indeterminate mammographic or sonographic findings who are recommended and for biopsy

Exclusion Criteria:

• Known contraindication to mammographic imaging
• women who are pregnant
• women who are lactating
• women who have significant existing breast trauma
• women who have breast implants
• Women under 18 years of age.
• women who had previous benign breast surgery within 1 year
• Males and children
• Women who are unable to understand or execute written informed consent
• Women who refuse to have a biopsy
• Women with any known renal disease - if an MRI is deemed necessary, a serum creatine will be checked prior to injection of contrast. Using the National Kidney Foundation recommendations, a glomerular filtration rate (GFR) greater than 60 may safely receive intravenous gadolinium-based MRI contrast. Those individuals with a GFR >30 and <60 can receive the contrast but at a reduced dose (typically half). Those with a GFR <30 will not receive MRI contrast and will not undergo the exam. Breast MRI must be done with contrast if evaluating for cancer. Several factors can affect the GFR such as age, body size, creatinine, renal status and will be calculated from the blood drawn. GFR is the final determinant and a creatinine greater than 1.6 usually has a GFR that precludes a Breast MRI with contrast. The final determinant will be the GFR.

Women scheduled for biopsy based on a suspicious mammogram and/or ultrasound. MBI results were compared to pathology.