The goal of the study is to compare the radiologist confidence level in evaluating patients with known breast lesions using a carbon nanotube x-ray based stationary breast tomosynthesis imaging device. The comparison will be made against conventional mammography acquired as a part of a standard clinical workup. One hundred patients who are to have a clinical surgical breast biopsy will be recruited for the study. A reader study will be performed to evaluate the ROC characteristics of the system.

Inclusion Criteria:

• Women at least 18 years old.
• Scheduled for breast biopsy of at least one breast lesion.
• Lesion detected on mammogram.
• Symptomatic by patient self-report, patient self-breast exam or clinical exam.
• Able to provide informed consent.

Exclusion Criteria:

• Male. (It is uncommon for men to present for imaging and the overwhelming majority of findings are non-cancerous and do not lead to biopsy; male breast cancer represents <1% of newly diagnosed breast cancer)
• Less than 18 years of age.
• Patient unable to give consent.
• Institutionalized subject (prisoner or nursing home patient).
• Any woman who is pregnant or has reason to believe she is pregnant or any woman who is lactating

Patients undergoing surgical breast biopsies for lesions detected on mammograms.