Magnetic resonance imaging of the musculoskeletal system: Part 3. The elbow.

Magnetic resonance imaging provides clinically useful information in assessing the elbow joint. Superior depiction of muscles, ligaments, and tendons as well as the ability to directly visualize nerves, bone marrow, and hyaline cartilage are advantages of magnetic resonance imaging relative to conventional imaging techniques. Ongoing improvements in surface coil design and newer pulse sequences have resulted in higher quality magnetic resonance images of the elbow. Traumatic and degenerative disorders of the elbow are well seen with MR imaging. The sequelae of medial traction and lateral compression from valgus stress include medial collateral ligament injury, common flexor tendon pathology, medial traction spurs, ulnar neuropathy, and osteochondritis dissecans. These conditions as well as lateral collateral ligament injury and lateral epicondylitis may be characterized with magnetic resonance imaging. Posttraumatic osseous abnormalities well seen by magnetic resonance imaging include radiographically occult fractures, stress fractures, bone contusions, and apophyseal avulsions. Magnetic resonance imaging also can be used to assess cartilaginous extension of fractures in children. Intraarticular loose bodies can be identified with magnetic resonance imaging, especially if fluid or contrast material is present within the elbow joint. Biceps and triceps tendon injuries can be diagnosed and characterized. Magnetic resonance imaging also can provide additional information regarding entrapment neuropathies about the elbow. Magnetic resonance imaging is perhaps most useful when patients have not responded to conservative therapy and therefore surgery and additional diagnoses are being considered.