Weight-Bearing Magnetic Resonance Imaging (MRI) for Analysis of Knee Osteoarthritis (OA)

Inclusion Criteria: * Female * 40 years and older * Subjects who are willing and able to comply with x-ray and MRI procedures * Evidence of a personally signed and dated consent document Additional inclusion for normal controls: * Infrequent knee pain, aching, or stiffness during the past year or infrequent use of medication for treatment of knee pain during the past year * No evidence of OA on either knee (i.e. K-L grade = 0 diagnosed by knee radiography) Additional inclusion for OA patients: * Pain, aching, or stiffness on most days of a month during the past year; or use of medication for treatment of knee pain on most days of a month during the past year * Kellgren-Lawrence Grade 2 or 3 of the study knee obtained on a Standard knee radiograph (with either the same or less severe OA, or no OA in the contralateral knee) Exclusion Criteria: * Subject is unable to undergo MRI because of contraindication * Women at risk of pregnancy * Weight greater than 250 lbs * History of surgery in the study knee * History of other diseases involving the study knee joint including inflammatory joint diseases, crystalline disease, and infection of the study knee