Inclusion Criteria:  Written informed consent obtained from participant or participant's legal representative and ability for participant to comply with the requirements of the study  Breast cancer patients with either natural or chemically induced menopause with stage 1-3 hormone receptor-positive breast cancers and on AI for at least one year OR healthy postmenopausal women  Breast cancer patients on aromatase inhibitors (AI) may fall into one of the three following groups:  Patients with knee pain with Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) >= 5, but no or minimal hand/wrist pain Patients with self-reported moderate or severe hand/wrist pain but no or only mild knee pain (WOMAC =< 7) Patients with no or minimal hand/wrist or knee pain (WOMAC =< 7) Age <= 70 years old Ability to read and complete quality of life surveys in English (or have a family member or friend available to translate and assist in completing surveys)  Exclusion Criteria:  History of prior traumatic injury at knee joint or severe degenerative joint disease or osteoarthritis defined as having a history of prior joint replacement or moderate to severe knee pain prior to initiation of AI History of claustrophobia Presence of a condition or abnormality that in the opinion of the investigator would compromise the safety of the patient or the quality of the data, including prior history of implanted devices with ferromagnetic objects