Elbow magnetic resonance imaging variants and pitfalls.

Imaging variants of the elbow and pitfalls can be disconcerting and can lead to diagnostic mistakes. Inhomogeneities in the magnetic field and coil position can result in signal changes that may simulate abnormality. Bone signal and morphology variants, such as the islands of red marrow and the pseudodefect of the capitellum and intraarticular inclusions such as plicae, may be mistaken for abnormal findings. Variations of the distal biceps and triceps tendons and different aspects of the ligaments and their insertions, as well as nonpathologic signal and width changes in the ulnar nerve, are other examples of common pitfalls in magnetic resonance imaging of the elbow.