Magnetic resonance imaging of soft tissue and cystic masses about the knee.

Magnetic resonance imaging (MRI) of the knee is the most frequently performed joint MRI examination. The use of MRI has revolutionized assessment of both intra-articular and periarticular musculoskeletal masses about the knee and has largely supplanted other radiologic methods of evaluation. The purpose of this article is to review the MRI appearance of the numerous types of soft-tissue and cystic masses that arise about the knee.