Musculoskeletal disorders: improving diagnostic accuracy with MRI.

Magnetic resonance imaging (MRI) is gaining wider acceptance for the diagnosis of musculoskeletal disorders in the elderly, including internal joint derangements, neoplasms, and osteonecrosis. For internal derangement of large joints such as the knee, MRI is a noninvasive alternative to arthrography and offers excellent visualization. It plays an important role in the diagnosis and staging of primary and secondary neoplasms, including both osseous and soft tissue sarcomas. MRI is also indicated for diagnosing osteonecrosis that cannot be detected using other imaging modalities.