MR imaging of patients with lateral epicondylitis of the elbow (tennis elbow): importance of increased signal of the anconeus muscle.

Increased signal intensity of the anconeus muscle on MR images in patients with chronic lateral epicondylitis suggests involvement of the muscle. Increased signal intensity is seen with edema, granulation tissue, and inflammation, which may explain the findings in this study. Our results are inconclusive as to whether this increased signal intensity contributes to the chronicity of patient symptomatology or is associated with abnormal elbow motion because of the symptoms.