Diagnosis of radial nerve palsy caused by ganglion with use of different imaging techniques.

Clinical features of six cases of radial nerve compression syndrome as a result of ganglion at the elbow are reported. The usefulness of different imaging techniques for detecting the location of ganglion is compared. The posterior interosseous nerve was involved in two patients, the radial sensory nerve in one patient, and both nerves in three patients. Ultrasonography, computed tomography, and magnetic resonance imaging revealed the location of the ganglion in every patient. Ultrasonography was most convenient for screening examination when it was difficult to clearly define a ganglion by palpation. In all patients, a ganglion arose from the anterior capsule of the elbow joint. Dynamic factors in addition to compression of the nerve by ganglion may influence occurrence of the nerve palsy.