This research study involves the use of a common breast imaging modality (magnetic resonance imaging, 'MRI') and is investigating its role in evaluating surgical decision making for breast cancer when it is performed with the patient in a new position (lying on one's back) as opposed to in the standard position (lying on one's stomach).

The procedure involved is called a supine breast magnetic resonance imaging (MRI).In this study, the investigators are evaluating the value of supine MRI in surgical decision making for women with breast cancer either undergoing upfront surgery or for those anticipating surgery after receiving neoadjuvant therapy.

The purpose of this study is to assess the value of supine breast MRI as a new imaging method to assist in surgical treatment planning. It is possible that the use of supine breast MRI will help your doctor see the size and location of tumors more accurately

Inclusion Criteria:

• Participants must be female
• Participants must have a pre-operative standard mammogram with or without ultrasound.
• Participants must have biopsy confirmed and clinical stage I, stage II, or stage III non-inflammatory breast carcinoma. If biopsy was done at an outside hospital, pathology will be reviewed at (BWH, BWFH)
• Patient must meet standard MRI guidelines and be able and willing to undergo MRI
• Participants must be candidates for definitive local therapy with breast conserving therapy or deemed as potential candidates following NAT (this takes into account tumor to breast size ratio appropriate for BCT, and the ability to undergo standard radiation therapy post-operatively).
• Study participants will be restricted to those aged ≥18 years old. This age group is selected because it encompasses the majority of women likely to receive neoadjuvant therapy
• Ability to understand and the willingness to sign a written informed consent document

Exclusion Criteria:

• Participants with a known BRCA 1 or 2 mutation.
• Participants with a known Li-Fraumeni or Cowden's Disease.
• Participants with prior mantle radiation.
• Participants with inflammatory breast cancer or multi-centric disease
• Participants who are pregnant.
• Participants who are already enrolled in a conflicting investigational trial
• Participants with known active collagen vascular disease.
• Participants with prior history of ipsilateral breast carcinoma treated with BCS and radiation therapy.
• Patients who have biopsy confirmed multi-centric disease.
• Participants who are unable to undergo MRI because of documented contra-indications for contrast-enhanced MRI, including but not limited to renal failure
• Participants who exceed the weight limit for the operative surgical table, 350 lbs or who will not fit into the 60 cm diameter bore of the MRI scanner.

1 month

The definition does not differ from the clinicaltirals.gov definitions.