Inclusion Criteria:

Women will have already undergone a breast physical examination, will
have had mammography within three months of their MR studies, and if they have not had
this study, will mammography after their MR examinations. Women with palpable or
mammographically-detected suspect breast lesions with or without breast implants will be
imaged. Women who are at high risk for breast cancer may also be included since these
women commonly require breast MRI screening. Since some patients may have had recent
core-needle biopsies and may have recent post-needle biopsy changes but plan follow-up
mastectomies or excision of the biopsy site (complete re-excision), we will include this
group. This will allow us to obtain the broad spectrum of post-needle biopsy findings
since it is a common procedure that is used prior to biopsy to evaluate patients for
potential cancer multicentricity or multifocality. Women who have already undergone
lumpectomy for breast cancer and have post-biopsy/post-radiation changes will be eligible
if they have mammographically-detected or palpable breast abnormalities which are
sufficiently suspicious to merit core needle or surgical biopsy.

Exclusion Criteria:The low incidence of male breast cancer precludes a significant
participation of men in the program and men will be excluded. Patients must be able to
complete an MR examination. Subjects will be interviewed by one of the investigators for
the usual contraindications to MR including pacemakers, metallic implants, severe
claustrophobia, aneurysm clips, pregnancy, current lactation, or other conditions
precluding proximity to a strong magnetic field. These patients will be excluded if these
contraindications are present.

Other patients will be excluded from the MR study if they have had an enhanced MR
procedure within 48 hours, had iodinated contrast within six hours, had known sensitivity
to MR contrast agents, are not likely to complete the study in full or have another
clinical reason which would preclude participation in the protocol.