Anterior interosseous nerve syndrome: appearance at MR imaging in three cases.

Three patients with symptoms attributable to anterior interosseous nerve syndrome underwent forearm magnetic resonance (MR) imaging. In all patients, short inversion time inversion-recovery, or STIR, images depicted increased signal intensity from some or all muscle groups innervated by the anterior interosseous nerve. In one patient, atrophy was depicted in these muscles. MR imaging may serve as a useful adjunct to electromyography in the investigation of anterior interosseous nerve syndrome.