Molecular Breast Imaging Guidance for Breast Biopsy for Patients With Breast Abnormalities

Inclusion Criteria: * PART I: Women aged 18 years or older * PART I: If able to become pregnant, negative pregnancy test within 48 hours prior to MBI biopsy procedure * PART I: Individuals who have previously (within the last 3 years) undergo an MBI study and were found to have at least one breast imaging finding on MBI that was subsequently shown (through additional imaging, biopsy or follow-up) to be benign in nature * PART I: Individuals who have agreed to participate in the study and who have signed the study-specific informed consent * PART II: Women aged 18 years or older * PART II: If able to become pregnant, negative pregnancy test within 48 hours prior to MBI biopsy procedure * PART II: Individuals who have previously (within the last 3 years) undergone an MBI study and were found to have at least one breast imaging finding on MBI that was subsequently shown (through additional imaging, biopsy or follow-up) to be benign or probably benign in nature * PART II: Individuals who had recent conventional imaging work-up including either x-ray mammography, ultrasound, MBI, or MRI of the breast and are found to have at least one breast imaging finding for which biopsy is required or recommended, specifically: * Individuals who have a breast abnormality(ies) on imaging with mammography, ultrasound, MBI, or MRI (as per American College of Radiology \[ACR\] Breast Imaging Reporting and Data System \[BIRADS\] 3, or higher) and requiring imaging follow-up or biopsy confirmation * PART II: Individuals who have agreed to participate in the study and who have signed study-specific informed consent Exclusion Criteria: * PART I: Women who are pregnant * PART I: Women who are currently lactating or discontinued breastfeeding \< 2 months prior to the study * PART I: Age less than 18 years * PART I: Women with breast implant(s) in the breast containing the lesion of interest * PART I: Inability to provide informed consent * PART II: Women who are pregnant * PART II: Women who are currently lactating or discontinued breastfeeding \< 2 months prior to the study * PART II: Age less than 18 years * PART II: Women with breast implant(s) in the breast containing the lesion of interest * PART II: Women who have recently (within the last 3 months) undergone biopsy of the breast finding * PART II: Women who are scheduled for a sentinel node procedure using radioactive Tc-99m within 24 hours of MBI-guided biopsy * PART II: Patients with contraindications for core biopsy and other invasive procedures such as blood coagulation disorders, infection, or who are unwilling to discontinue use of anticoagulant medication prior to the procedure * PART II: Inability to provide informed consent * PART II: Women who have had surgery on the study breast(s) within the past 12 months